List of Sites of Special Scientific Interest in Greater London

Frays River in Frays Farm Meadows

Greater London is split by the River Thames. The London region has a population of 7,512,400 within an area of 1,579 km², making it the second-largest populated region in the United Kingdom. However, even though it is one of the largest urban conglomerations in Europe, almost two-thirds of London is made up of greenspace and wetlands, consisting primarily of extensive areas of green belt, large parks and the Thames basin. As of January 2016, there are 37 sites designated within this Area of Search, 30 of which have been designated for their biological interest and 7 for their geological interest.

In England, the body responsible for designating Sites of Special Scientific Interests is Natural England, which chooses sites because of their fauna, flora, geological or physiographical features. Natural England took over the role of designating and managing SSSIs from English Nature in October 2006 when it was formed from the amalgamation of English Nature, parts of the Countryside Agency and the Rural Development Service. The data in the table is taken from Natural England's website in the form of citation sheets for each SSSI.

For other counties, see List of Sites of Special Scientific Interest by Area of Search.

Key

Interest

• B = a site of biological interest
• G = a site of geological interest

Access

• YES = free public access to all or most of the site
• PP = free public access to part of the site
• PL = public access at limited times
• NO = no public access

Other classifications

• GCR = Geological Conservation Review
• EWT = Essex Wildlife Trust
• HMWT = Herts and Middlesex Wildlife Trust
• KWT = Kent Wildlife Trust
• LB = Listed building
• LNR = Local nature reserve
• LWT = London Wildlife Trust
• NNR = National nature reserve
• RHPG = Register of Historic Parks and Gardens of Special Historic Interest in England
• RSPB = Royal Society for the Protection of Birds
• SAC = Special Area of Conservation
• SM = Scheduled Monument
• SPA = Special Protection Area
• WWT = Wildfowl & Wetlands Trust
• WT = Woodland Trust

Sites

Site name	Photograph	B	G	Area	Public access	Location	Other classifications	Map	Citation	Description
Abbey Wood	100px		Y	6.3 hectares (16 acres)	YES	Abbey Wood TQ481786	GCR	Map	Citation	The site is late Palaeocene and early Eocene 50 to 60 million years ago. It has yielded one of only two Palaeocene birds found in Britain, the holotype of Marinavis longirostris, a large Procellariiform.
Barn Elms Wetland Centre	100px	Y		29.9 hectares (74 acres)	YES	Barnes TQ228770	WWT	Map	Citation	The site is a mosaic of wetland areas, with open water, marshland and reed beds. It has nationally important numbers of shovellers, and other birds include gadwalls, little grebes, grey herons, mute swans and little ringed plovers.
Bentley Priory		Y		55.1 hectares (136 acres)	YES	Stanmore TQ156297	LNR	Map	Citation	The dominant grasses in the site are common bent, red fescue and Yorkshire Fog. Uncommon wild flowers include greater burnet, great burnet and spotted orchid. There are many birds including buzzard, spotted flycatcher, and bullfinch
Brent Reservoir	100px	Y		68.6 hectares (170 acres)	YES	Hendon TQ217873	LNR	Map	Citation	The reservoir is mainly significant for its nesting birds, especially for its nesting great crested grebe. Other birds include coots, little grebes, tufted ducks and gadwalls. There are also areas of swamp and wet woodland.
Bushy Park and Home Park		Y		541.0 hectares (1,337 acres)	YES	Teddington TQ159692		Map	Citation	The site has nationally important dead and decaying wood invertebrates, including the beetles Aeletes atomarius, Stenichnus godarti and Trichonyx sulcicollis. It also has ancient trees and acid grassland.
Chingford Reservoirs	100px	Y		316.3 hectares (782 acres)	NO	Chingford TQ371953		Map	Citation	The reservoirs are majoring wintering grounds for wildfowl, including nationally important populations of shoverllers and great crested grebes. There are also important numbers of Goldeneye (duck), tufted ducks and goosander. A total of over 85 species of wetlands birds have been recorded.
Crofton Woods	100px	Y		76.6 hectares (189 acres)	YES	Crofton TQ437665		Map	Citation	It is a large area of ancient woodland on London Clay, which supports many types of trees, shrubs and herbs. Trees in the ancient wood are mainly oak and hazel, with a central area of former fields. It has high botanical diversity, including fourteen species of sedge, and a rich invertebrate fauna.
Croham Hurst	100px	Y		33.6 hectares (83 acres)	YES	South Croydon TQ338632		Map	Citation	This site, on a steep hill, has a diverse community on its lower slopes of plants dominated by oak and hazel on rich soils overlying chalk. Further up the trees are mainly beech on Thanet Sands, and towards the top the main trees are oak and birch on the acidic Blackheath pebble beds.
Denham Lock Wood	100px	Y		6.3 hectares (16 acres)	YES	Denham TQ05863	LWT	Map	Citation	It is a poorly drained wet woodland and fen site which is skirted by the Frays River. The main trees are alder and crack willow in the wetter areas, and elsewhere oak and ash with a shrub layer of hazel. In winter wildfowl are visible and in spring many flower species. Invertebrates include red cardinal beetles, banded demoiselles and the rare and protected Desmoulin's whorl snail.
Downe Bank and High Elms	100px	Y		86.8 hectares (214 acres)	YES	Downe TQ438610 TQ446625	KWT, LNR, LB	Map	Citation	Downe Bank is a meadow and woodland area associated with Charles Darwin, who lived locally. High Elms is woodland which has locally uncommon species, such as green hellebore, bird's-nest orchid, spurgelaurel and yellow bird's-nest.
Elmstead Pit			Y	0.05 hectares (0.12 acres)	NO	Elmstead TQ42327066	GCR	Map	Citation	The pit exposes an important layer of the Oldhaven or Blackheath Beds laid down about 50 million years ago during the Eocene epoch. It has a rich and diverse selection of fossil fauna from a sub-tidal estuarine environment. Fossils include molluscs, sharks' teeth and fish scales.
Epping Forest		Y		1,728.0 hectares (4,270 acres)	YES	Epping TL475035 – TQ405865	EWT, NCR SAC	Map	Citation	The forest has one of the few major examples of lowland wood pasture in England, with areas of pasture and wetland. According to Natural England it "supports a nationally outstanding assemblage of invertebrates, a major amphibian interest and an exceptional breeding bird community".
Farthing Downs and Happy Valley	100px	Y		120.5 hectares (298 acres)	YES	Coulsdon TQ303572	SM	Map	Citation	This site has chalk and neutral grasslands and an area of ancient woodland. It has the largest British colony of the rare wildflower greater yellow-rattle, and nationally scarce herbs. Eight species of orchid have been recorded.
Frays Farm Meadows	100px	Y		28.2 hectares (70 acres)	YES	Denham TQ057861	LWT, LNR	Map	Citation	The Meadows are one of the few remaining examples of unimproved wet alluvial grassland in Greater London. The linear features, river, embankment, ditches and hedges, contribute to the rich diversity of plants and animals. Mammals on site include the nationally endangered water vole.
Gilbert's Pit	100px		Y	5.2 hectares (13 acres)	YES	Charlton TQ418786	GCR, LNR	Map	Citation	This is an important Lower Tertiary site, displaying one of the most complete sequence of sediments in Greater London. The Paleocene Thanet and Woolwich Beds date to around 55 million years ago. Some of the beds yield many fossils of plants, sponges, molluscs, fish and reptiles.
Hainault Forest		Y		136.0 hectares (336 acres)	YES	Hainault TQ477938		Map	Citation	This is mainly pedunculate oak and hornbeam on Claygate beds, glacial gravels and boulder clay. There is a varied flora and fauna, including many bird species, including nightingales, wood warblers and spotted flycatchers.
Hampstead Heath Woods	100px	Y		16.6 hectares (41 acres)	YES	Hampstead TQ270875 TQ271870		Map	Citation	The site has many old and over-mature trees, and extensive dead wood which provides a habitat for invertebrates, including the nationally rare jewel beetle Agrilus pannonicus. The main trees are sessile oak and beech. The shrub layer is dominated by holly and rowan.
Harefield Pit			Y	1.8 hectares (4.4 acres)	YES	Harefield TQ049898	GCR	Map	Citation	This is described by Natural England as an important Tertiary site in the London Basin, which displays a sequence through the Upper Chalk, Reading Beds and London Clay. It is the only known source of charophytes in the Reading Beds, and these have potential for correlation with other localities in Europe.
Harrow Weald	100px		Y	3.7 hectares (9.1 acres)	YES	Harrow Weald TQ147929	GCR	Map	Citation	It provides the most complete exposure of Pleistocene gravel beds above the Claygate Beds, the youngest layer of London Clay. They were formerly thought to have been of marine origin but recent research has cast doubt on this view. It is considered a key site for further studies.
Hornchurch Cutting			Y	0.8 hectares (2.0 acres)	YES	Hornchurch TQ547874	GCR	Map	Citation	This is at the southern edge of the Anglian ice sheet 450,000 years ago, the most extreme ice age during the Pleistocence ice ages of the last 2.58 million years. It is the type site for Hornchurch Till, boulder clay laid down by the ice sheet in the Ingrebourne Valley.
Ingrebourne Marshes		Y		74.8 hectares (185 acres)	YES	Hornchurch TQ532835	EWT, LNR	Map	Citation	The site is the largest area of freshwater marsh in Greater London. It is very diverse, with large areas of reed sweet-grass, common reed swamp, wet neutral grassland and tall fen. There are two nationally rare Red Data Book species, the hoverfly Anasimyia interpuncta and the scarce emerald damselfly Lestes dryas.
Inner Thames Marshes	100px	Y		479.3 hectares (1,184 acres)	YES	Purfleet TQ531800	RSPB, LNR	Map	Citation	The site has a wide variety of breeding and wintering birds, with internationally important levels of wintering teal. The marshes also have rare plants and invertebrates, such as the pondweed Potamogeton pusillus and the emerald damselfly.
Kempton Park Reservoirs		Y		25.6 hectares (63 acres)	NO	Kempton Park TQ118707	LNR	Map	Citation	Waders that breed regularly include northern lapwing, common redshank, ringed plover and little ringed plover. The first successful inland breeding in the British Isles of pied avocet was at this reservoir. Other birds recorded include smew, garganey, Temminck's stint, spotted crake and red-necked phalarope.
Keston And Hayes Commons	100px	Y		26.6 hectares (66 acres)	YES	Keston TQ417643		Map	Citation	This site has both acid dry and wet neutral grassland. Heather on dry infertile soil has unusual lichens. There are also areas of valley mire, a brook and ponds.
Mid Colne Valley	100px	Y		132.0 hectares (326 acres)	YES	Harefield TQ043896	HMWT	Map	Citation	The site is significant for its breeding wetland birds and over-wintering water birds. Wintering birds which are present in nationally important numbers are great crested grebes, cormorants, shovellers and tufted ducks, and the number of gadwalls is internationally significant. The River Colne is important for bats, particularly Daubentons.
Old Park Wood		Y		16.7 hectares (41 acres)	YES	Harefield TQ046913	HMWT	Map	Citation	The site is dissected by small valleys and has a variety of types of soil and plants. The trees are mainly oak, birch, hornbeam and ash. Golden saxifrage and marsh marigolds grow along small streams and there is a pond which is important for dragonflies and invertebrates.
Oxleas Woodlands		Y		72.7 hectares (180 acres)	YES	Eltham TQ442760	LNR	Map	Citation	The site is mature woodland on London clay. Most of it is hazel with pedunculate or sessile oak, or birch and pedunculate oak. Insects include the beetles Oligota flavicormis and Scolytus intricatus, and the fly Dolichopus wahlbergi.
Richmond Park	100px	Y		856.0 hectares (2,115 acres)	YES	Richmond TQ200730	NNR, SAC, RHPG	Map	Citation	The park is an important refuge for wildlife, including woodpeckers, squirrels, rabbits, snakes, frogs, toads, stag beetles and many other insects plus numerous ancient trees and varieties of fungi. It is particularly notable for its rare beetles.
Riddlesdown	100px	Y		32.0 hectares (79 acres)	YES	Kenley | TQ330600		Map	Citation	This is the largest area of calcareous scrub in Greater London, with a herb-rich chalk grassland. There are two nationally rare herbs, early gentian (Gentianella anglica) and round-headed rampion. Invertebrate species include the scarce Roesel's bush-cricket.
Ruislip Woods	100px	Y		305.4 hectares (755 acres)	YES	Ruislip TQ081892	NNR	Map	Citation	This site has some of the largest unbroken blocks of semi-natural woodland in Greater London, almost all on clay soils, and it also has areas of wetland and grassland. It has some rare plant and insect species, including the orchid broad-leaved helleborine and the herb common cow-wheat.
Ruxley Gravel Pits		Y		18.7 hectares (46 acres)	NO	Orpington TQ474700	KWT	Map	Citation	There are four water filled pits with areas of fen. Over 500 plants species have been recorded and 169 birds, out of which 53 are breeding species. There are also 23 butterfly species, 23 dragonfly and over 500 beetles. Water quality is high.
Saltbox Hill	100px	Y		22.2 hectares (55 acres)	YES	Biggin Hill TQ402604 TQ408607	LWT	Map	Citation	Much of it is chalk grassland which is rich in plants which are rare in Greater London, and it is one of only two sites in London which has the Dark Green Fritillary butterfly. Ten species of orchid and over thirty of butterflies have been recorded. The site also has an area of woodland.
Syon Park	100px	Y		21.5 hectares (53 acres)	PL	Isleworth TQ176766		Map	Citation	This site is tide meadow of reed-grasses, with rye-grass and meadow-grass on higher ground. There are many small ditches, and it is used by many over-wintering birds and has a number of rare invertebrate species, including uncommon flies.
Walthamstow Marshes	100px	Y		36.7 hectares (91 acres)	YES	Walthamstow TQ352875		Map	Citation	The site has areas of semi-natural wetland and some of drier grassland. There are a variety of marshland breeding birds, and butterflies such as the Essex skipper. Species such as the Roesel's bush-cricket are indicators of ancient marshland.
Walthamstow Reservoirs	100px	Y		178.3 hectares (441 acres)	NO	Walthamstow TQ351892	SPA	Map	Citation	The Walthamstow Reservoirs support the most notable variety of breeding wetland birds among all of London's drinking water reservoirs. Great crested grebe, pochard, tufted duck, coot, yellow wagtail, sedge warbler and reed warbler are all regular breeding visitors.
Wansunt Pit			Y	1.9 hectares (4.7 acres)	PP	Dartford TQ514736 TQ515738	GCR	Map	Citation	The site exposes the Dartford Heath Gravel, and the relationship of this exposure to the Swanscombe sequence and the Thames Terraces is a controversial issue in Thames Pleistocene studies. Stone tools have been found of Homo Heidelbergensis, dating from the Hoxnian Stage, an interglacial period between 424,000 and 374,000 years ago.
Wimbledon Common	100px	Y		346.5 hectares (856 acres)	YES	Wimbledon TQ227720	SAC	Map	Citation	The common has an extensive area of wet acidic heathland, and other areas of dense semi-natural woodland on clay. There are many streams and plants uncommon in the London area. Other features are bog mosses and locally important breeding birds.

See also

• List of Local Nature Reserves in Greater London
• London Wildlife Trust