Corporate report

Durham's National Nature Reserves

Updated 5 March 2021

Applies to England


Cassop NNR is one of the best magnesian limestone grassland sites in County Durham. The site lies entirely within the lower Magnesian Limestone, a very restricted rock formation in Britain. It outcrops only in a very narrow band which closely follows the A1 trunk road from mid-Nottinghamshire, north towards County Durham. Within Durham this exposed area broadens out into a triangular area known as the East Durham Plateau.

Main habitats: lowland grassland
Area: 6.8 hectares
Management: Natural England

Access is by permit only.

Features of interest

Cassop supports a range of grassland, scrub and woodland communities but of greatest importance is the Magnesian Limestone grassland, established both as primary grassland and secondarily in the abandoned quarries.

Characterised by the abundance of blue moor-grass (Sesleria albicans) with a rich assemblage of other species including fragrant orchid (Gymnadenia conopsea), cowslip (Primula veris), rock rose (Helianthemum nummularium) and quaking grass (Briza media).
Rare and local species recorded include bird’s-eye primrose (Primula farinosa) and butterwort (Pinguicula vulgaris).


Please note there are no parking facilities available at this site.

Access is via a farm track off Church Street north-west of Quarrington Hill some 900m north beyond the junction of the Half Moon public house on the B6291, map reference NZ 328 385.


Volunteers play an important role in the management of Cassop NNR, helping with a wide variety of tasks. To find out more contact


For more information contact the NNR site office on tel: 0191 586 0004
Telephone enquiries: 0300 060 3900

Castle Eden Dene

This mysterious tangled landscape of trees, rocky outcrops and steep cliffs is a sensational survivor of ‘the wildwood’ that once covered much of Britain. Yew, oak, ash and dying elm create a home for other plants and creatures. 10,000 years of wild growth in a deep gorge has created a place you can explore again and again.

Main habitat: woodland

Features of interest

The reserve covers 221 hectares of woodland and lowland grassland, where post-glacial melt waters have carved out some spectacular limestone cliffs and gorges.

The steep crumbling sides of the gorge are made of soft magnesian limestone.

The Dene is 3.5 miles (5.6 kilometres) long and is the largest of a series of valleys which run down to the coast between Sunderland and Hartlepool, reaching the sea at Denemouth.

Often there is no water at the bottom of the gorge, as Castle Eden Burn is now seasonal and disappears into the limestone rock during the summer.

Castle Eden Dene is home to an extraordinary variety of birds, more than 450 species of plants, and mammals including roe deer and fox.

Although the Dene itself it is not suitable for wheelchairs, Natural England has opened a new, short, easy access path that starts at the lodge car park. All paths can be muddy and slippery after bad weather.


The reserve is near Route 1 (Peterlee Link) of the Sustrans National Cycle Network. There are bike racks at Oakerside Dene Lodge. No bikes are allowed in the Dene, where the steep paths are dangerous for cycling.

Walk from Peterlee bus station and cross at the pelican crossing. Follow the tarmac footpath through the pine trees to the right of the Peterlee Lodge Hotel. Follow the footpath for approximately 1.5 miles (2.4km) keeping the Dene on your left. Take care crossing the road into Stanhope Chase to the lodge.

Castle Eden Dene is signposted from the A19 and from Peterlee town centre. The postcode for the Dene car park is SR8 1NJ.


The following bye-laws are in force to protect the wildlife of the Dene:

  • cycling and horse riding are not allowed on the reserve, except on the route shown on the map
  • camping or lighting fires is prohibited
  • no firearms of any sort, including air rifles, are to be carried or used in the Dene.
  • do not remove any plants or wood
  • take all litter home with you
  • dog control orders are strictly enforced within the Dene. It is an offence to let your dog foul this ancient woodland without clearing up afterwards. Offenders will be prosecuted


Take great care when you walk on the reserve and make sure you stay on the paths. There are steep hills and cliffs and the ground can be difficult underfoot at times, so it’s essential that you have sturdy footwear with good grip.

Most paths are waymarked but you should allow plenty of time for your visit to avoid being on the site after dark.

School and community groups

The reserve has its own education program, offering a wide range of classes covering most aspects of the national curriculum.

We support the ‘Every child matters’ policy and ‘Learning Outside the Classroom’ initiative. You can accredit biodiversity work towards the ‘Eco-Schools Award’ scheme. We can adapt all activities to suit the needs of the children.

We can design visits for secondary school and university students to complement the programs that they are studying.


As a volunteer you can:

  • help with a wide range of practical conservation tasks
  • help to patrol the 12 miles of footpaths
  • take part in practical conservation tasks
  • help with educational activities, public events and guided walks

Contact the reserve office for more information.


Telephone: 0191 586 0004

Castle Eden Dene National Nature Reserve
Natural England
Dene Lodge
2 Stanhope Chase

Derwent Gorge and Muggleswick Woods

The site contains some of the finest ancient oak woodlands in north-east England as well as some unique semi natural grasslands. It is designated as Site of Scientific Special Interest for these features in addition to its lichen assemblage.

Main habitats: ancient oak and ash woodland

Features of interest

The zonation of woodland types, from dry acid sessile oak woods on the higher ground to the flushed lime rich ash woodland and wet alder woodland in the lower slopes, creates a rich diversity of woodland flora and fauna. The site is recognised as regionally important for epiphytic lichens, with over 60 species recorded.

Red kites and buzzards may be seen gliding above the canopy with spotted and pied flycatcher, redpoll, siskins and wood warblers within the woods. Dippers, kingfishers and goosanders frequent the river and its tributaries, whilst historically the site has had populations of red squirrel and there are roe deer in the woods.


The reserve lies 4 miles (6.5 kilometres) south-west of Consett in County Durham. Take the A629 through Castleside towards Stanhope, after half a mile turn right towards Muggleswick. Enter the NNR along a public footpath which begins a further mile and a quarter (2 kilometres) along this road on the right hand side.

A number of footpaths cross the reserve (a permit is required away from these paths). There are many high-sided, steep and slippery banks within Derwent Gorge. You are advised to keep to the public rights of way which provide a safe route through the woodlands.

There are no formal car parks although there are several small lay-bys with enough space for up to two cars along the Castleside to Muggleswick road. There are better car parking facilities available at nearby Derwent Reservoir.

The site is occasionally used by community groups and school groups for activities such as tree planting and litter picking. If you would like to use the site for your group, or for any enquiries regarding volunteering or educational opportunities at the North Pennines NNRs, contact the reserve manager.


Telephone: 01833 622374

Martin Furness
Reserve Manager
Widdybank Farm
Langdon Beck
Forest in Teesdale
Barnard Castle
DL12 0HQ

Durham Coast

The reserve is made up of 5 parcels of land on the Durham Coast. The area is noted for its striking geological features and grassland that is home to numerous wild flowers and butterflies. The area is also home to many birds and supports an important breeding population of little terns.

Main habitats: coastal and lowland grassland

Management: parts of the Durham Coast reserve are managed by Durham County Council and the Durham Wildlife Trust.

Features of interest

The reserve is part of the wider Durham Heritage Coast area.

Further information about the NNR, its wildlife and how to visit can be found on the relevant pages of the Durham County Council and Durham Wildlife Trust.


Gail Craig Durham Heritage Coast Partnership

Email: Telephone: 0300 026 8131

Moor House - Upper Teesdale

Remote, dramatic and exhilarating - the landscape of the Pennines forms the backbone of England, and this reserve gives you the chance to see some of its most spectacular geological formations, waterfalls and panoramic views.

Main habitats: upland, including blanket bog, northern hay meadows and limestone grassland.

Features of interest

The reserve is famous for the rare spring gentian as well as England’s largest juniper wood. The rare black grouse also breeds here, as does the golden plover and ring ouzel. Rare arctic-alpine plants, remnants of the ice-age, can be found and there are many species of wading birds such as lapwing, curlew, redshank and golden plover.

Explore using the network of well-signed public footpaths and find 3 dramatic waterfalls: Cauldron Snout, High Force and Low Force.

For more information about the reserve, including its history and geology, seasonal highlights and details on how to get there, see Natural England’s pages on Moor House - Upper Teesdale in the National Archive. These pages include an information leaflet giving directions for 3 nature trails at the reserve.


For your own safety, keep to the waymarked routes – there are hidden mineshafts in the area.

Beware of unexploded ammunition in the MOD Danger Areas. Access to the Mickle Fell area (MOD Danger Area) is by permit only – applications to:

The Range Officer
Warcop Training Area
Warcop, Appleby
CA16 6PA

Take care with children – especially along the river bank where water levels can rise quickly, and in the juniper woods around High Force, where there are unfenced cliff edges hidden amongst the bushes.


Sustrans National Cycle Route 68, the Pennine Cycleway, the Eden Valley Cycleway and the C2C all run close to the Moor House side of the NNR.

Secure bike parking is available at Cow Green Reservoir, at Tees Bridge on the Garrigill to Moor House track, and at the NNR entrance on the Knock to Great Dun Fell road.

A limited bus service runs from Middleton-in-Teesdale to Langdon Beck (and Cow Green on request), see Traveline. There is no bus service to the Moor House side of the reserve.

The Upper Teesdale side of the NNR can be reached from the B6277 Middleton-in-Teesdale to Alston road. The nearest car parks are at Cow Green Reservoir (along a minor road signposted from Langdon Beck), High Force, Hanging Shaw and Bowlees.

Access to the Moor House side of the NNR is along minor roads from Garrigill and Knock, and then on foot or bicycle to the NNR.

School and community groups

Visits from primary schools are linked to the curriculum and support the Every Child Matters agenda and Learning outside the Classroom initiative. Biodiversity work can be credited towards the Eco School award scheme. All activities can be adapted to suit the needs of the children.

Secondary school visits can be designed to complement the programmes that the students are studying.

Young people can take part in badge and award work or practical conservation sessions.

The reserve also welcomes adult group visits. A volunteer Green Guide or member of staff will be able to accompany your visit or to introduce the area to your group – please book ahead so this can be arranged.

For more information or to book a school/group session contact the NNR site office on 01833 622374.


The reserve runs a programme of practical conservation tasks for volunteers. Work days are usually held midweek, about once a month from March to December.

All you need is a packed lunch, outdoor clothing, boots or wellies (some can be borrowed from the reserve). The tasks start at 10am and finish by about 3.30pm. The reserve may be able to help with transport.

It is essential to book onto a task in advance and to confirm meeting points – phone the reserve on 01833 622374.


For more information about the reserve please contact the reserve office: Widdybank Farm Langdon Beck Forest-in-Teesdale Barnard Castle Co. Durham DL12 0HQ, tel 01833 622374.


Thrislington Plantation NNR is the most valuable wildlife site on County Durham’s magnesian limestone.

Main habitats: lowland grassland.

Features of interest

This rock originally formed in a shallow tropical sea some 250 million years ago, and now outcrops in only a few places in northern England. It has weathered to form thin lime-rich soils on which unique grasslands have developed. Over the years the effects of agricultural change, mining and quarrying have reduced the limestone grassland to a tiny remnant of its original area.

The limestone grassland at the site supports scarce plant species, including blue moor grass, small scabious, rock-rose, and dark red helleborine.

Insects abound with many unusual species present. Two notable examples are northern brown argus butterfly and glow-worm.

The reserve is adjacent to a working quarry which makes some access restrictions necessary. Organised groups must pre-book. For more details (and a copy of a species guide for the site), email the reserve manager Joe Davies

The best time to visit is between May and late August.


The reserve is 1 kilometre west of the A1(M), 10 kilometres south of Durham, 12 kilometres north east of Bishop Auckland, and 1 kilometre east of Ferryhill village, on the A167. By car, access to the site is via minor roads from the A167 and the village of Cornforth, 1.5 kilometre to the north.

The site is immediately south of a working quarry operated by Lafarge Aggregates. There is a car park adjacent to the quarry offices but this is only available to pre-booked groups. There is a laybay near the reserve’s entrance on the minor road to Cornforth.

The nearest train stations are Durham and Bishop Auckland.

For bus services see Traveline.


For more information contact the NNR site office on tel: 0191 586 0004