Cosmeston Country Park

In Glamorgan, we need look no further than the Cosmeston Country Park to see the potential of rehabilitated quarries to accommodate wildlife and give unbounded pleasure to visitors.
 Limestone Downs: Commons, Farms and Woods, by Mary Gillham, published 1991.

Mary's expertise as a naturalist played an important role in helping to convert land exploited by industry into an excellent country park with some areas protected and conserved as Sites of Special Scientific Interest at and around the Cosmeston lakes. Mary was involved in the planning of Cosmeston as a Country Park and offered her expert advice on the maintenance of the environment for wildlife. Mary was also included in the planning management of the Cogan plantation, woodland on the west side of the country park. The first map of Cosmeston Mary has in her archive is from 1968 when the quarries were still active, however, at this time there were already proposals for a new country park around the Cosmeston lakes, including the creation of a footpath around the Western lake. Read on to find out how Mary helped to shape Cosmeston Country Park into what it is today...


On this page:

A brief history of Cosmeston
1970s Cosmeston
1980s Cosmeston
1990s Cosmeston
Then and Now in Cosmeston



Read a brief History of Cosmeston on the Vale of Glamorgan Council website and a more in depth account of Cosmeston through the 12th-16th century can be found in 'The Manors of Sully, Cosmeston, Penarth and Cogan'. A replica Medieval Village, also present at Cosmeston, is a popular attraction of the park, this information booklet describes the attributes of the village and the Vale of Glamorgan Council website also provides information on the Cosmeston Medieval Village.

Quarrying for limestone ceased in 1969 and the quarry closed in 1970 with the withdrawal of 'Blue Circle', the previous owners of the quarry site. The excavation of limestone during quarrying left four large holes at Cosmeston. The two southern quarry holes naturally filled with water from underground springs to create the West and East Cosmeston lakes (as well as the wetlands around them). The lakes are divided by a bridge, forming the main footpath, known as 'Mile Road'. The two northern quarry holes were used for landfill of household waste from 1964 to 1978, though the tipping of refuse at Cosmeston has now been permanently terminated. The sites were landscaped to create the northern West and East paddocks.

The South Glamorgan County Council and the Vale of Glamorgan Borough Council obtained the land to start work towards the development of a country park. The land was developed under Countryside Commission funding to become a Country Park. The park has a plaque by the Eastern lake dedicated to the Countryside Commission for their contribution to Cosmeston Lakes Country Park in 1978. During the landscaping of the new park, the first evidence of the medieval village was unearthed and an archeological exploration was undertaken. Housing estates have since occupied the cement factories.

The park was developed in 3 phases (existing land use map). The transition of the sites from limestone quarry to Country Park was partly achieved on 1st August 1978, when Phase one of the park was opened to the public. The public was restricted to approximately 60 acres around the two lakes. Within the first phase a temporary car park was provided, as well as boardwalks over the wetlands, footpaths around both lakes, observation hides, wardens' accommodation and a temporary slipway for boats.

In March 1979, work commenced on reclaiming the remainder of the site. This consisted mostly of reclaiming and landscaping land covered in limestone spoil. When the reclamation works ceased, the area was seeded, trees were planted, and was then opened to the public. Phase two focused on the west of the park, including Cogan wood. Phase 3 saw the remainder the eastern and northern areas reclaimed, addressing the dangerous and unsightly features of the site, and re-seeding and planting trees on a large scale throughout the park. The entirety of Cosmeston Lakes Country Park was opened to the public in 1982 and has over 110 acres of lakes, woodland and meadows open to the public all year round. In 2013, Cosmeston Lakes Country Park was designated a Local Nature Reserve.




Mary's involvement with Cosmeston:


A document by Steve Young from c.1973 states that the large quarries in Cosmeston have filled with water and that the area is being used by breeding Coots and Moorhens. Hundreds of Gulls are visiting Cosmeston to bathe in the water and feed on the rubbish tips. A variety waterfowl had been seen at the lakes. He writes that "in years to come when the water has matured vegetation and fauna of its own, much more is likely to be seen. This will then be one of the most interesting parts of the country."

Mary's archive shows herself and colleagues taking at least 95 recording trips to Cosmeston park (although this is likely a large understatement of the actual number of visits), the first of Mary's visits being on 22nd March, 1973. At this time Cosmeston would have been a developing country park in which Mary, her colleagues, Glamorgan Naturalists' Trust, South Glamorgan County Council, Vale of Glamorgan Borough Council and many volunteers contributed to the development and management of the environment and wildlife.

On her first recorded visit to Cosmeston Mary notes the variety of birds at the lakes and surrounding wetlands, the same species as recorded by Young earlier. She makes note of the causeway that separates the West and East lakes and how this will be good for the birds. She also comments that due to the nature of the lake as a water filled quarry, much vegetation won't grow because the lake is too deep, the quarry cliffs going sheer to great depth except where trucks used to drive out up ramps. The best vegetation is in the Northwest corner of the West lake where the water is shallower, however fences around these areas are broken so access is easily gained. She writes that the hedges around the central track are well established and the Eastern lake appears to have reached a more mature phase of vegetation colonisation due to the reed mace in the wetlands. At the end of the document is written "This area has potentialities and might be put forward as a reserve if no-one wants it" (later the document had been added to stating that the lakes and surroundings had been designated as a country park in 1974). Also in this document is an extensive list of species that Mary observed on her first visit to Cosmeston.

Cosmeston quarry East Lake. View East from causeway, 1973

Cosmeston Quarry, View over West Lake to East lake through gap in causeway from shallows where lorries drove up.

Cosmeston Quarry, West pool (1973). Juncus articulatus (left) Juncus inflexus right

Mary contacted the Department of Environment and Planning for the South Glamorgan County (12th December 1974) requesting information about the quarries and the creation of the lakes: 1. Depth of the two lakes, 2. Date when working finished, 3. Date when flooded- were there pools there before, 4. where lorries drove out, 5. Future proposals for use and development. Do these incorporate partial restriction of public access for birds etc.? However, she did not receive much useful information from this (negations on ownership were taking place at the time; the northern quarries at this point were being used as rubbish tips). Later (9th January, 1975) Mary received a letter from Ewart Parkinson, director of Environment and Planning for the county of South Glamorgan informing her that the had little information towards turning Cosmeston into a country park They thank her for supplying information on the flora and fauna in the area.

A Gwent Trust newsletter published an article by Mary, here she describes the devastating treatment of the Cosmeston landscape, but even so Mary writes of the many species currently surviving in the lakes and the surrounding environment.

On 7th September 1975, Mary received the information on the felling of a number Elm trees due to Dutch elm disease, these she writes were replaced by poplars. This document also demonstrates the exploitation and mismanagement of the environment at this time, not helped by a drought. Families were bathing in the lakes and adolescents were diving off the bridge, running the risk of injury due to underwater debris. Power boats were in use on both lakes which were a danger to the bathers. Motor bikes were driven around the park and when they broke they were dumped in the lake. The marsh around East lake had overgrown and the birds no longer used it, visitors were also starting to make paths through it.

Fossil bivalve shells in Lias stone. Cosmeston Quarry

Rose, Valerian, Ox-eye. Cosmeston quarry, June 1976

Mary, in 1976, began to obtain data from fellow recorders Jim Lewis and Ivor Penberthy on some uncommon plants they had found at the developing Cosmeston County park, such as Ophrys apifera - the Bee orchid.

Her first report, written in November 1976, to the county council regarding the future of Cosmeston can be read here, along with her own phase map of development.

Cosmeston quarry East lake, June 1976

Cosmeston quarry West lake, June 1976

Teasel, Valerian, Oxeye. Cosmeston West Lake 1976

Rosa canina by Cosmeston Quarry, West Lake. June 1976

Power boat menace. Cosmeston from peninsula, West side and from South side of West lake. 1976

Cosmeston West quarry. Signs of pollution. Water is acidic (Hydrogen sulphide), 1976

In November 1976, Birds were breeding by the lakes, in the hedges and in Cogan wood (Cogan mostly comprised of Elm trees). The northern rubble tips were still present. Motor cycling and public swimming were still occurring around the park. Wire fencing was still not secure, allowing public access to some restricted areas and Cosmeston still needed a proper car park. Peter Leonard, at this time was head of the Department of Environment and Planning for South Glamorgan county council. Ivor Penberthy writes to Mary (in March 1977) that "there is virtually no protection for the wildfowl except brambles". Mary also begins taking her extra-mural classes around Cosmeston.

Cosmeston Lake and Cogan plantation. November 1976

The Glamorgan Naturalists' Trust applied for permanent use of the park for its members in c.1977. The Trust also compiled a list of matters for consideration for Cosmeston Country park

Cosmeston lakes and peninsula from West. Bramble growth on lias rubble. November 1976

Cosmeston. Early stage in Lias rubble colonisation by South end of West lake. November 1976

13th May 1977. Glamorgan Naturalists' Trust (Wyn Thomas-South Area Chairman for GNT) was contacted by South Glamorgan and Vale of Glamorgan Borough Council in connection with Cosmeston Country park. There was to be a meeting to speak on conservation and environmental matters and that the Glamorgan Naturalists' Trust were invited to attend and represent. Mary along with Mr. Roy Perry, Mrs. Kay White, Dr. David Duckett, Mrs. Lindo Longhelt, Dr. June Chatfield, Mr. Stephen Howe, Mr. Keith Bowen were invited to represent the trust. Mary (member of the South Area committee) along with Kay White (Hon. Secretary of the trust) represented the Trust on 25th May 1977. A letter (14th May 1977) from the South Glamorgan Director of Environmental Planning to Wyn, writes, "with reference to the above and to the help that your trust has been able to give in the past to this Council in the investigation of the ecology of the country park site. You will be aware that it is the intention to devote the eastern lake at Cosmeston to active recreation, and the western lake to the conservation and peaceful enjoyment of nature", the 3 phase plan was also sent. 

Mary continued to write reports in 1977 on information she obtained about the developing Country park, with aid from her colleagues:

Problems continued in the park: The Mute swans' eggs were stolen in 1978. Birds were nesting in Ash trees, as opposed to the dead Elms. Anglers were introducing fish species with unknown effects on the lakes food chain.

Early in 1978, Mary writes that the "duck walks, paths, in fact everything in phase 1 almost to be done through the prime of spring and summer months in readiness for opening in August 1978. Exactly the wrong time, Jan-Mar 1979." "Trees have been planted alongside Cogan plantation to make wood continuous, instead of the mosaic of trees, shrubs and grass which we advised to absorb more people". "Even more extraordinary because the natural tree regeneration at the northeast corner of Cogan plantation has been bulldozed off - the area I had earmarked as being of particular value for the course of natural plant succession". Throughout this time Mary continues to correspond with planning bodies on the planning and management of the park, especially concerning tree and shrub planting and preserving.

Lias rubble. West lake, Cosmeston, May 1978

Cosmeston winter 1978-1979. An orchid corner has established southwest of West lake. Landscaping of the mounds of spoil heaps with bulldozers is ongoing. A peninsula stretching into the Western lake had become an island. Cogan wood at this time was still restricted from public use (part of phase 2). Ivor had recovered over 50 bee orchids northeast of the Eastlake in 1978 which have been moved elsewhere to protect them from accidental damage by bulldozing.

Ian Smith, at this time an assistant warden for Cosmeston Country park, wrote to Mary (Ian's Letter) inquiring about the future management of the Country Park and for her continuing support.

Mary gave advice to the County of South Glamorgan (County Planning Officer, A. J. Plant) concerning a pilot tree planting scheme at Cosmeston, Mary responds to a planned map of tree planting, she mainly advices (correspondent letters here) to cut the number of conifers and increase deciduous and requested that no more non-native sycamores be planted.

Cosmeston Country Park: Tree Planting Plan from the Council

June Chatfield also sends some notes to Mary on recorded species at Cosmeston park (1st January 1978). She writes, "This site has the potential to become an interesting habitat if managed with the interests of natural history in mind" and that "the richness of flora and fauna is partly relayed to the limestone bedrock". Mary suggests to the planners for a boardwalk acros the wetlands to prevent trampling and also marked paths around the western lake would prevent the destruction of orchids by being trodden on the public. Motor bikes were still present on the footpaths and she suggests that angling should be prevented on the western lake.

16th March 1978. A reply from the County Planning officer, A.J. Plant on Pilot planting tree scheme. Plans were revised and amended with suggestions from Mary on the 21st December. The numbers of conifers have been reduced, sycamores will not be planted around the western lake, and a variety of indigenous species have been incorporated. In April 1978, management of the clearing of brambles was undertaken around the East lake.

Cosmeston, Three colours of soil on levelled North bank. East lake, March 1978

Cosmeston, Swan islet in West lake before path made. March 1978 

26th April 1978, Mary visits Cosmeston Country Park with Mr. Osborne of Vale of Glamorgan Council and the warden. Steve Young and June Chatfield continue to record species and send them to Mary. “These swampy bits are to be preserved - crossed only by boardwalk - and look interesting”, Mary writes here.

13th July 1978, The area on the North shore of East lake was topsoiled and rich passerine habitat have established in the in woods around West lake. 

Phase 1 of Cosmeston Country park (Southern area including both lakes) was officially opened to the public in August 1978.

11th December 1978. Ivor writes about Cardiff naturalist society-botanical section involvement. The botanical section has an interest in the park, such as organising monthly visits to record plants.

Glamorgan Naturalists Trust criticise poor park management of flora. Attractive and interesting flora that had established was obliterated by the north part of the eastern lake by bulldozing during the first phase of development. Plans were made to move and restore flora by park management to other locations.

December 1978, All fishing was banned in the West lake except by causeway (Mrs. Margaret Box Chairman of joint management committee was involved). "Ivor, Geoff Curtis of CNS Botany section and I and possibly, Steve and Dr Findlay to survey with the new report and maps in hand- in readiness for phase 2 and 3 as there is money which has to be used pronto-or it will be lost-so programme speeded up".

Dead Elms. Cosmeston East Side, 1979

22nd January 1979. The beginning of the discussion for phase 2 by Ivor Penberthy (here). In March 1979, the process of reclaiming 100 acres of derelict land as part of phase 2 began.

21st June 1979. Mary, Ivor and John Zehetmayr press on with the recording of wildlife and commenting on the management of the Country park. Unauthorised human activity continues, such as swimmers and the use of power boats on the lakes, as well as motor bikes being driven over some of the still present northern spoil heaps. Even though the lakes have a rich variety of wildlife, old quarry waste was still present. However, Mary comments that there is “Excellent development of water vegetation in both lakes, particularly Westlake”.

Hawthorn meadow. East Cosmeston, 1979

Bulldozers on phase 2 Cosmeston from East. July 1979

Cosmeston Lakes. July 1979.

July 1979. The boardwalks South of East lake now cross a flowering sea of meadow sweet. Mary also regularly receives correspondence from the Cardiff naturalists society about Cosmeston and the flora there. Mary also writes on this date that "the main part of phase 2 had been levelled and 3 bulldozers were smoothing and levelling. No plant remained".

30th August 1979. Mary is sent plans from Vale of Glamorgan Borough Council - D.G. Clark (Director of parks and recreation administration) for the landscaping of the western lakes, prepared with the help of Ivor Penberthy and Olive Brown (Cardiff Naturalists trust) and is asked for further suggestions to the plans. Mary’s advice is used directly on the treatment of the wet hollows, i.e. the excavation of the existing wet hollows to encourage the further colonisation of wetland flora and fauna; this was done by removing, storing and replacing some of the soil from the wet lands in order to retain the wetlands original soil composition. Later Mary receives planting plans and further landscaping plans for Cosmeston. She is happy with these plans with nothing more to suggest and is glad that the eastern hawthorn meadow and overgrown hedges are remaining intact. A report on the Landscape proposals for the Western Lake

A letter is also sent from the County of South Glamorgan County planning officer A.J. Plant concerning the orchids at Cosmeston County park. Ian Smith, the now Deputy warden for Cosemston Country park compiled a Report on Orchids found at Cosmeston and an Orchid species map - June/July 1979.

Cosmeston Orchids. Bee Orchids (left) and Spotted Orchid (right)

Cosmeston 1979: Landscaping West of West Lake

Winter 1979, follows up information with Ian Smith. The fishing lines were still causing a threat to birds and in a phone call from Dr. Findlay on the state of Cosmeston park as “seem to be keeping the wild bits wild” to his satisfaction, except bulldozers still were causing accidents, stating that the “bulldozer driver didn’t know what he was doing”.



In February 1980, during the development of the meadow paddocks, the bulldozers were burying orchids and natural limestone flora under 2 feet of imported topsoil. Mary took strong objection to this as she felt that the limestone flora would take at least 10 years to grow back and that the landscapers seemed to know little about conservation. Mary's thoughts on the destruction can be read here

July 1980. The central lane is still designated a road, though efforts still being made to get it degraded to bridle and footway. More flora is growing back over the phase 2 northern pastures and in the Cogan plantation.

Cosmeston boardwalk and frogspawn. Ivor Penberthy and Ian Smith. February 1980

Cosmeston. Sully Brook, South of West Lake. February 1980

Cosmeston, South West of West Lake. February 1980

Glamorgan Naturalists Trust newsletter (1980): Nature and Recreation, A discussion of a site where both are blended

Observations on Plant Life by the Cardiff Naturalists' Society, Botanical Section

7th January 1981. Ivor (Botanical Section, Cardiff Naturalists Society) received a letter from Glamorgan naturalist trust David Gregsoll (Field officer for the trust) thanking him for providing recent botanical information from Cosmeston.  “I must admit I was amazed to find a species list as long as 338 higher plants and containing so many interesting species. The information was passed on to Mr Barry Long of the Countryside Commission.”

22nd January 1981. Letter from A.J. Plant to Ivor, thanking him for his observations of plant life and habitats at Cosmeston park. “I think that the observations will be of value to the Director of Parks and Recreation Administration, Vale of Glamorgan Borough Council, as the managing authority of the Park”.

1983. Mary reports on the good grass cover on the contoured northern paddocks as part of phase 3, but some quarry spoil is still present in the southwestern parts of the country park.

26th January 1984. Mary receives plans from Clark (Director of leisure and Amenities, Vale of Glamorgan borough council) concerning Cogan wood management plan for development and requesting Mary's advice so that the plans may be amended if required in light of Mary's observations.

Cogan wood management plan (1984). Cogan wood had not been managed since it was planted around the end of the last century. Elm trees are dominant (with Oaks in some western areas), however, due to the adverse effects of Dutch Elm disease, a considerable percentage of these elms have since died, many Elms have been felled as a result. Birch, Ash, Hawthorn and Elder are now abundant in the woods with Poplar and Oak on the boundaries. Some locations have become ecologically rich with flora and are considered worthy of protection. Cogan Wood: 1878-1968

Some objectives for Cogan wood management statements, derived from survey work.

  1. To protect and enhance visual amenity of the woodland
  2. To encourage and develop an ecologically balanced woodland by maintaining and improving the diversity of indigenous tree and shrub species.
  3. To develop the maximum potential of recreational uses within the woodland
  4. To maximize the educational potential of Cogan woodland
  5. To encourage a wider diversity of habitats for flora and fauna within the woodland
  6. To maximise visitor capacity of the woodland
  7. To provide interpretation and information sheets to increase public awareness and enjoyment of the woodland environment.

Map of the Cogan Wood Management Plan

June 1984. A letter is written from the Nature Conservancy Council announcing drafted proposals for Sites of Special Scientific Interest (SSSI) in Cosmeston Lakes Country Park. Mary receives the information for her own interest and could offer comments, she agrees with all the SSSI plans.

September 1984. Cosmeston is scheduled to have SSSI. A car park is fully established and activities using the lakes and surrounding areas are managed.

1985: The SSSI is now officially declared. The sites include

  1. All the West Lake conservation area
  2. North to include dragonfly pools and Cogan wood
  3. Wood North of East Lake – (said to be excellent – entry over stile which warden wishes he hadn’t put in, though walkers are sticking pretty well to the path).
  4. The Hawthorn field. This is an unconnected outlier – with a gap in between - (The gap, the recontoured, newly sown slope, carry cattle in June 1985).
  5. Marshy field with boardwalk South of East Lake

Public access to conservation areas are restricted to protect the wildlife breeding areas and delicate plants.

Later in this document, Mary writes “The new man in charge in the Vale is said to be very sympathetic to the conservation cause, so things should be looking up. The park is a splendid conservation asset now that it is growing back in – to dinkum limestone grassland. The face-lift of contouring and sowing was necessary to remove the derelict land aspect and hasten regeneration. As I so often told Ian Smith “It all comes right in the end if you wait long enough”.”

Cosmeston swans. East lake, 1985

1985. Mary writes, "the composition of the sown sward on leveled, top-soiled slope North of East Lake is in its seventh year. The enclosure at East end of pond growing nicely, A sea of ox-eye daisies. A great patch of Linium bienne in fruit. Several splendid clumps of bee orchids. Wire fence protection around plants and orchids to prevent trampling. Healthy bird population. Mute swans continue to have cygnets. Dragon fly ponds doing well, dragonfly pool proper, at foot of 2 unlevelled spoil mounds. This area (the old rubbish tip which is still a hollow) is a delight, banks of blossoming bramble- alive with butterflies. A lot of the level, rubbly open soil still visible-this drying out earlier than that of haw-field".

Boardwalks across marsh lands South of East Lake. July 1985

Cosmeston field North of East Lake. July 1985

Cosmeston pools East of Cogan woods. July 1985

Cosmeston. Wild carrot, East of Cogan woods. An old tip site, 1985

Field north of Cosmeston West lake. 1985

Picnic site South West of Lake. Cosmeston 1985

The Botanical section of CNS provides field meeting report in 1986 on Cosmeston Park, which includes an extensive variety of plants.



Zehetmayr continues to record the variety of plants, especially orchids at Cosmeston.

21st April 1992. The visitor centre is now fully functional; as is the Medieval village which is managed by the Glamorgan and Gwent archeologists, later the village is managed by Country Park local authorities. Trees have grown up around the car park and Mary writes that “Cosmeston is a litter free zone, fiercely enforced by wardens and it was delightful to see not a scrap of rubbish anywhere”. There is no public access in areas around the West Lake and other conservation areas in the park; grass and orchids are “coming up everywhere even on bare rubbish tips, have beautifully grassed over, few species though, not mown or managed in any way, soil infertility keeps it sparse"

September 1992, written by Andy Kendall and Linda Nottage, The ducks, geese and swans at the Cosmeston lakes have become very tame, although there are concerns over “The interbreeding between wild and feral ducks, it was felt by many that it would be nice to remove the ferals, but trapping or shooting them would lead to such a public outcry that it is unlikely to ever happen”.

A Cosmeston warden also informs Mary of the loss of almost all the ducklings, baby coots, moorhens and grebes to the feral American mink that had taken up residence and reared a family “If only the ‘do-gooders’ who release these menaces into the wild from the fur farms would think a little before the act, a lot of suffering and depletion of wild creatures would be avoided."

February 1993. The Mute swans at the lakes have been present since Cosmeston became a Country Park, throughout this time the male cob has been with three partners. His first partner died of lead poisoning, his second was shot, at this time the male and his third partner are continuing rear cygnets.

Cosmeston Lakes Country Park illustrated brochures from Mary's archive: Brochure 1Brochure 2, Brochure 3 drawing, Brochure 4.

An overview of the current habitats and wildlife of The Vale of Glamorgan can be found here


Changes in the park

Cosmeston East paddock in July 1979 (Phase 2 of the Country park development) and in 2017


Cosmeston West lake in 1973 and in 2017


Cosmeston West lake from the western side in November 1976 and November 2017


Cosmeston West of West lake in February 1980 and in November 2017


View of Cosmeston West Lake, from North of the lake in September 1987 and in November 2017


Present day (2017) North of the Western Lake