
Adur Estuary is a 62.2-hectare (154-acre) biological Site of Special Scientific Interest on the western outskirts of Shoreham-by-Sea in West Sussex. Part is a Royal Society for the Protection of Birds nature reserve.

Arne RSPB reserve is a 5.634-square-kilometre (1,392-acre) nature reserve and Site of Special Scientific Interest (SSSI) maintained by the RSPB and located in Dorset. It was notified as an SSSI in 1986 and the estuarine reedbeds within the site are designated as a national nature reserve. The reserve occupies the Arne Peninsula, which protrudes into Poole Harbour. Adjacent to the site is the village of Arne, although the nearest major settlement is the town of Wareham.

Aylesbeare Common is a protected area in Devon, England. It is composed largely of heathland and woodland, interspersed with a few streams and ponds. There are several species of birds and insects which live in Aylesbeare Common, including a wider variety of butterfly species than in any other RSPB reserve.

Bempton Cliffs is a section of precipitous coast at Bempton in the East Riding of Yorkshire, England. It is run by the RSPB as a nature reserve and is known for its breeding seabirds, including northern gannet, Atlantic puffin, razorbill, common guillemot, black-legged kittiwake and fulmar. There is a visitor centre.

Berney Marshes and Breydon Water RSPB reserve is a nature reserve managed by the Royal Society for the Protection of Birds (RSPB). Berney Marshes is situated south of the River Bure while Breydon water is the combined estuary of the River Waveney and the River Yare inland from Great Yarmouth in Norfolk, England.
Blacktoft Sands RSPB reserve is a nature reserve in the East Riding of Yorkshire, England. It is managed by the Royal Society for the Protection of Birds, which leases the site from Associated British Ports.

Breydon Water is a 514.4-hectare (1,271-acre) biological Site of Special Scientific Interest at Great Yarmouth, Norfolk. It is a Local Nature Reserve, a Ramsar site and a Special Protection Area. It is part of the Berney Marshes and Breydon Water nature reserve, which is managed by the Royal Society for the Protection of Birds (RSPB).

Buckenham Marshes RSPB reserve is a nature reserve located on the northern bank of the River Yare in the English county of Norfolk. The reserve is located around 8 miles (13 km) south-east of Norwich near the village of Buckenham. The site, which is in The Broads, is managed by the Royal Society for the Protection of Birds.

Burton Mere Wetlands is a nature reserve on the Dee Estuary straddling the border between Cheshire, England and Flintshire, Wales. It is run by the Royal Society for the Protection of Birds (RSPB) and incorporates the older Inner Marsh Farm reserve. It lies near the village of Burton, about 3 kilometres (1.9 mi) south of Neston. It has all been developed by the RSPB and includes a large area of mixed wetland habitats, bluebell woodlands, and arable fields all managed to attract wildlife.

Coombes Valley RSPB reserve is a nature reserve, run by the RSPB, near the town of Leek in Staffordshire, England. It is best known for its breeding woodland birds, including common redstart, wood warbler and pied flycatcher. It is also home to the nationally scarce argent and sable moth, a priority species in the UK's Biodiversity Action Plan.

Coquet Island is a small island of about 6 hectares, situated 1.2 kilometres (0.75 mi) off Amble on the Northumberland coast, northeast England.

Dingle Marshes is a 93 hectares wildlife reserve on the North Sea coast of the English county of Suffolk. The reserve is located between Dunwich and Walberswick, approximately 4 miles (6.4 km) south-west of Southwold. The marshes make up part of the Suffolk Coast National Nature Reserve along with reserves at Walberswick and Hen Reedbeds. They are owned jointly by the RSPB and Suffolk Wildlife Trust and are managed by these two organisations and Natural England. The site is in the Dunwich Heaths and Marshes Nature Conservation Review site, Grade I, the Minsmere-Walberswick Ramsar internationally important wetland site, the Minsmere to Walberswick Heaths and Marshes Special Area of Conservation, and the Minsmere-Walberswick Special Protection Area under the European Union Directive on the Conservation of Wild Birds.

Fairburn Ings Nature Reserve is a protected area in Yorkshire, England, which is noted for its avian biodiversity. The reserve has recorded around 280 bird species, remarkable for an inland site in the United Kingdom. This is explained by the site being on migration routes as well as the diversity of habitats.

Fen Drayton is a small village between Cambridge and St. Ives in Cambridgeshire, England, and between the villages of Fenstanton and Swavesey.

Fen Drayton Lakes is a complex of lakes, lagoons, ponds and a river, situated close to Fen Drayton, Holywell and Swavesey in Cambridgeshire, England. The complex was formerly a gravel extraction site until 1992 when gravel production ceased and the pits were allowed to flood to provide a nature reserve and bird sanctuary.

Fore Wood is a 20.9-hectare (52-acre) biological Site of Special Scientific Interest north-west of Hastings in East Sussex. It is part of the Royal Society for the Protection of Birds nature reserve of the same name.
Fowlmere is a Royal Society for the Protection of Birds nature reserve between Fowlmere and Melbourn in Cambridgeshire. It is designated a 39.9 hectare biological Site of Special Scientific Interest called Fowlmere Watercress Beds.

Frampton Marsh is a nature reserve in Lincolnshire, England. The reserve is situated on the coast of The Wash, some 4 miles from the town of Boston, between the outfalls of the Rivers Welland and Witham, and near the village of Frampton. Most of the reserve is managed by the RSPB with part managed by the Lincolnshire Wildlife Trust. There is a small visitor centre at the entrance to the reserve.

Freiston is a village and civil parish in Lincolnshire, England. The population of the civil parish at the 2011 census was 1,306. It is situated approximately 2 miles (3 km) east from Boston. The Greenwich Prime Zero meridian line passes between the village and Hobhole Drain.

Garston Wood is a 34-hectare (84-acre) woodland nature reserve on the border between Dorset and Wiltshire in England, around 3 km (2 mi) north of the village of Sixpenny Handley, owned by the Royal Society for the Protection of Birds to protect species living in the region. The reserve is a mixture of ancient woodland and managed coppices and scrubland. To help maintain the park, the RSPB sets annual population targets for certain breeding pairs of birds, and manages the forest by clearing out taller and non-native trees.

Geltsdale RSPB reserve is a nature reserve in Geltsdale, Cumbria, England. The Royal Society for the Protection of Birds manages the site for upland birds such as the hen harrier and black grouse.

Ham Wall is an English wetland National Nature Reserve (NNR) 4 kilometres (2.5 mi) west of Glastonbury on the Somerset Levels. It is managed by the Royal Society for the Protection of Birds (RSPB). Since the last Ice Age, decomposing plants in the marshes of the Brue valley in Somerset have accumulated as deep layers of peat that were commercially exploited on a large scale in the twentieth century. Consumer demand eventually declined, and in 1994 the landowners, Fisons, gave their old workings to what is now Natural England, who passed the management of the 260 hectares Ham Wall section to the RSPB.

Havergate Island is the only island in the county of Suffolk, England. It is found at the confluence of the River Ore and the Butley River near the village of Orford. It is a marshy nature reserve run by the Royal Society for the Protection of Birds (RSPB) and is known for its population of avocets and terns. It is part of the ecologically important Alde-Ore Estuary and has protected conservation status as part of a national nature reserve, SSSI, SAC, SPA, Ramsar Site and is also a part of the Suffolk Coast and Heaths AONB.

The Hayle Estuary is an estuary in west Cornwall, England, United Kingdom. It is one of the few natural harbours on the north coast of south-west England and during the prehistoric and early medieval periods was important for trade and the movement of people and ideas.

Hodbarrow RSPB Reserve is a nature reserve run by the Royal Society for the Protection of Birds on the edge of the Lake District National Park in Cumbria, England. It is on the Duddon Estuary near the town of Millom.
Lakenheath Fen RSPB reserve is located on the Norfolk/Suffolk border in England, between Lakenheath and Hockwold cum Wilton adjacent to Lakenheath railway station.

Langstone Harbour is a 2,085.4-hectare (5,153-acre) biological Site of Special Scientific Interest in Hampshire. It is an inlet of the English Channel in Hampshire, sandwiched between Portsea Island to the south and west, Hayling Island to the south and east, and Langstone to the north. It is part of Chichester and Langstone Harbours Ramsar site, Special Protection Area and Nature Conservation Review site, Grade I. Parts of it are in Solent Maritime and Solent and Isle of Wight Lagoons Special Areas of Conservation. Three areas are Local Nature Reserves, Farlington Marshes West Hayling and The Kench, Hayling Island. Two areas are nature reserves managed by the Hampshire and Isle of Wight Wildlife Trust, Farlington Marshes and Southmoor Nature Reserve

Leighton Moss RSPB reserve is a nature reserve in Lancashire, England, which has been in the care of the Royal Society for the Protection of Birds since 1964. It is situated at Silverdale near Carnforth, on the edge of Morecambe Bay and in the Arnside and Silverdale Area of Outstanding Natural Beauty.

RSPB The Lodge is a nature reserve run by the RSPB, named after the building there, The Lodge, which is their headquarters. It is located south-east of the town of Sandy, Bedfordshire, in England.

Lodmoor is a Site of Special Scientific Interest (SSSI), RSPB reserve and country park in Dorset, England. The country park features a visitor centre, model railway and pitch and putt golf course. The SSSI has a wetland habitat with native birds that are rare in the UK and a range of migratory species.

Marazion Marsh is a Royal Society for the Protection of Birds (RSPB) reserve situated in a shallow river valley, half a kilometre to the west of Marazion, Cornwall, UK. It is separated from the coast by a shingle bar and small sand dune system and contains Cornwall's largest reed bed.

RSPB Minsmere is a nature reserve owned and managed by the Royal Society for the Protection of Birds (RSPB) at Minsmere, Suffolk. The 1,000-hectare (2,500-acre) site has been managed by the RSPB since 1947 and covers areas of reed bed, lowland heath, acid grassland, wet grassland, woodland and shingle vegetation. It lies within the Suffolk Coast and Heaths Area of Outstanding Natural Beauty and the Suffolk Heritage Coast area. It is conserved as a Site of Special Scientific Interest, Special Area of Conservation, Special Protection Area and Ramsar site.

Nagshead is a woodland reserve, located on the western edge of Parkend, in the Forest of Dean, Gloucestershire, and is home to RSPB Nagshead. The site is listed in the 'Forest of Dean Local Plan Review'.

Nagshead is a 120.12-hectare (296.8-acre) biological Site of Special Scientific Interest and is located near Parkend, in the Forest of Dean, Gloucestershire, and was notified in 1972. It lies within the Forest of Dean Forest Park and is part held as a reserve by the Royal Society for the Protection of Birds (RSPB). The SSSI is a relatively small area of the much larger nature reserve of RSPB Nagshead, which is a 1,250 acres (510 ha) site owned and managed by the RSPB and the Forestry Commission. The SSSI lies to the east of the Nagshead Plantation and consists of two units of assessment by Natural England.

Nene Washes is a 1,522.1-hectare (3,761-acre) biological Site of Special Scientific Interest on the bank of the River Nene east of Peterborough in Cambridgeshire. It is also a Ramsar internationally important wetland site, a Special Area of Conservation, a Special Protection Area and a Nature Conservation Review site. An area of 280 hectares is managed by the Royal Society for the Protection of Birds. The total area of the Ramsar site is 1,517 hectares.

North Warren RSPB reserve is a nature reserve run by the Royal Society for the Protection of Birds (RSPB) in Suffolk, England. It lies on the Suffolk coast on the north edge of the town of Aldeburgh and to the south of Thorpeness and includes the Aldringham Walks area of heathland to the north. It is within the Suffolk Coast and Heaths Area of Outstanding Natural Beauty (AONB) and the Suffolk Heritage Coast area. Noted for its populations of Eurasian bittern, European nightjar and other bird species, it covers a range of coastal habitats and is protected with SSSI, SPA conservation status.

Northward Hill is a 52.5-hectare (130-acre) biological Site of Special Scientific Interest Kent. It is a Nature Conservation Review site, Grade 2, and is also designated High Halstow National Nature Reserve The site is managed by the Royal Society for the Protection of Birds.

RSPB Dearne Valley Old Moor is an 89-hectare (220-acre) wetlands nature reserve in the Dearne Valley near Barnsley, South Yorkshire, run by the Royal Society for the Protection of Birds (RSPB). It lies on the junction of the A633 and A6195 roads and is bordered by the Trans Pennine Trail long-distance path. Following the end of coal mining locally, the Dearne Valley had become a derelict post-industrial area, and the removal of soil to cover an adjacent polluted site enabled the creation of the wetlands at Old Moor.

Otmoor RSPB Reserve is a nature reserve, managed by the RSPB, between Beckley and Oddington, within the wider area of Otmoor, in Oxfordshire, England. The reserve was established in 1997 and restored large areas of marshland from what had previously been farmland. The RSPB reserve covers around 1,000 acres (400 ha).

Ouse Washes is a linear 2,513.6 hectare biological Site of Special Scientific Interest stretching from near St Ives in Cambridgeshire to Downham Market in Norfolk. It is also a Ramsar internationally important wetland site, a Special Protection Area under the European Union Birds Directive, a Special Area of Conservation, and a Nature Conservation Review site, Grade I. An area of 186 hectares between March and Ely is managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire, and another area near Chatteris is managed by the Royal Society for the Protection of Birds. The Wildfowl & Wetlands Trust manages another area near Welney.
Pulborough Brooks is a 160-hectare (400-acre) biological Site of Special Scientific Interest south of Pulborough in West Sussex. It is part of the Pulborough Brooks nature reserve, which is managed by the Royal Society for the Protection of Birds. It is also part of the Arun Valley Ramsar site, Special Area of Conservation and Special Protection Area.
Radipole Lake is a lake on the River Wey, now in the English coastal town of Weymouth, Dorset, once in Radipole, the village and parish of the same name. Along the western shore of the lake, and between Radipole and the town centre of Weymouth, now lies the modern suburb of Southill.

Read's Island is an island situated just outside the Ancholme sluice, on the Humber Estuary in England. The Lincolnshire Trust suggest it is an artificial island, and a report from 1979 says that it was reclaimed. However, the site was for many years a large sandbank going by the name of "Old Warp" and is shown on the 1734 Customs Map of the Humber where Read's Island now lays, and extending further downstream.

Bowling Green Marsh is a nature reserve located on the confluence of the River Exe and the River Clyst, near the town of Topsham in Devon. It is managed by the RSPB.

Brading Marshes nature reserve is the only Royal Society for the Protection of Birds (RSPB) reserve on the Isle of Wight, England. Situated on the east coast of the Island, behind Bembridge Harbour, it was acquired in 2001 and is a mix of lagoons and ditches, reed beds and meadows, with a fringe of ancient woodland. This marsh is the site of a wetland restoration project by the RSPB.

Rye Meads is a 58.5 hectare biological Site of Special Scientific Interest (SSSI) in Rye House, Hertfordshire. It is one of series of wetlands and reservoirs situated along the River Lea, to the north-east of London. It is part of the Lea Valley Ramsar site and a Special Protection Area.

Sandwell Valley is an area of green belt in the county of West Midlands, England, on the border of Birmingham and West Bromwich, with Walsall at its northern end.

Sandwell Valley RSPB reserve is a nature reserve, run by the RSPB, in Sandwell Valley, to the north of West Bromwich, in the Sandwell borough of West Midlands in England. It is adjacent to, and shares its main lake with, Sandwell Valley Country Park and near the settlement of Hamstead.

Sandy Warren is a 16.4 hectare biological Site of Special Scientific Interest in Sandy in Bedfordshire. It is part of The Lodge, a nature reserve run by the Royal Society for the Protection of Birds (RSPB), and named after the RSPB headquarters called The Lodge at the same site.
Snettisham RSPB reserve is a nature reserve in the care of the Royal Society for the Protection of Birds, situated near Snettisham in the county of Norfolk, England, north of King's Lynn, and close to Sandringham. It faces The Wash, a large estuary. In autumn and winter, the big tides of the Wash pushes up hundreds of thousands of wading birds onto the Norfolk coast. The nature reserve's bird lagoons provide a safe habitat for them.

St Aidan's is a 400-hectare (990-acre) nature park located between Leeds and Castleford in West Yorkshire, England. The land was formerly an opencast coal mining area that was flooded in 1988, after the riverbank collapsed. Repairs and remediation required its own act in Parliament to allow the necessary works to go ahead. Mining ceased at St Aidan's in 2002.

St Bees Head RSPB Reserve at St Bees Head, Cumbria, England, is a coastal site which provides a home for thousands of seabirds under the care of the RSPB. The birds include kittiwakes, fulmars, guillemots, razorbills, cormorants, puffins, shags and herring gulls. It is the only breeding place in England for black guillemots. The rock pipit, which breeds on rocky coasts, is known to breed in only one other site in Cumbria.

Strumpshaw Fen is a nature reserve managed by the Royal Society for the Protection of Birds (RSPB). It is situated at Strumpshaw on the River Yare in the English county of Norfolk around 6 miles (9.7 km) east of Norwich. The Buckenham Marshes RSPB reserve borders the reserve to the east.

Surlingham Church Marsh is a small RSPB nature reserve in the Norfolk Broads, England. It is part of Yare Broads and Marshes Site of Special Scientific Interest

Titchwell Marsh is an English nature reserve owned and managed by the Royal Society for the Protection of Birds (RSPB). Located on the north coast of the county of Norfolk, between the villages of Titchwell and Thornham, about 8 km (5.0 mi) east of the seaside resort of Hunstanton, its 171 hectares include reed beds, saltmarshes, a freshwater lagoon and sandy beach, with a small woodland area near the car park. This internationally important reserve is part of the North Norfolk Coast Site of Special Scientific Interest (SSSI) and the Norfolk Coast Area of Outstanding Natural Beauty (AONB), and is also protected through Natura 2000, Special Protection Area (SPA) and Ramsar listings.

Wallasea Wetlands is a reclaimed wetlands area located in Essex, England. It has been created as part of a government-funded wetlands scheme to halt the decline of wild and endangered birds caused by the drainage and development of former wetland sites. It is the largest man-made marine wetland area in the United Kingdom.

West Sedgemoor or West Sedge Moor is an area of the Somerset Levels, in Somerset, England, around 8 miles east of Taunton, which approximately coincides with the West Sedgemoor biological Site of Special Scientific Interest, a 1,016 hectare site notified as an SSSI in 1983. It is a flat, low-lying area of fields and meadows separated by water-filled rhynes and ditches. It is subject to controlled flooding in winter. It is drained by the River Parrett.

Wolves Wood is a woodland near Hadleigh, Suffolk. It is one of 7 ancient woodland areas within Suffolk. An ancient woodland is defined as a site that has been continuously occupied by woodland from the year 1600 or before.