List of the largest Sites of Special Scientific Interest in England
This is a list of the largest Sites of Special Scientific Interest in England in decreasing order of size. A lower threshold of 100 hectares or one square kilometre has been used.
Sites more than 10,000 hectares in size
Site name |
Area of Search |
Reason for designation |
Area[ a] |
Grid reference |
Year in which notified |
Map[B] |
Biological interest |
Geological interest |
Hectares |
Acres |
The Wash |
Norfolk / Lincolnshire |
Y |
|
63,135.0 |
156,010.0 |
TF550400 |
1972 |
|
North York Moors |
North Yorkshire / Cleveland |
Y |
|
44,087.7 |
108,943.1 |
NZ680000 |
1998 |
|
Humber Estuary |
Humberside |
Y |
Y |
37,000.6 |
91,430.5 |
TA216184 |
2004 |
|
Dark Peak |
Derbyshire / Greater Manchester / South Yorkshire / West Yorkshire |
Y |
Y |
31,852.9 |
78,710.2 |
SK110960 |
1951 |
|
Morecambe Bay |
Cumbria / Lancashire |
Y |
|
30,287.5 |
74,842.0 |
SD360700 |
1975 |
|
Upper Solway Flats and Marshes |
Cumbria / ? |
Y |
Y |
29,950.5 |
74,009.3 |
NY160610 |
1988 |
|
The New Forest |
Hampshire / Wiltshire |
Y |
Y |
28,947.4 |
71,530.6 |
SU298081 |
1959 |
Map |
South Pennine Moors |
West Yorkshire / Great Manchester / Lancashire / North Yorkshire |
Y |
Y |
20,938.1 |
51,739.2 |
SD920300 |
1994 |
|
Salisbury Plain |
Wiltshire / Hampshire |
Y |
|
19,689.9 |
48,654.8 |
SU070500 |
1975 |
Map |
Breckland Forest |
Norfolk / Suffolk |
Y |
Y |
18,078.7 |
44,673.4 |
TL819839 |
2000 |
|
Severn Estuary |
Avon / Somerset + others |
Y |
Y |
15,950.0 |
39,413.3 |
ST480830 |
1976 |
|
Upper Teesdale |
County Durham |
Y |
Y |
14,035.6 |
34,682.7 |
NY830320 |
1951 |
|
Moorhouse and Cross Fell |
Cumbria / County Durham |
Y |
Y |
13,707.0 |
33,870.7 |
NY715365 |
1990 |
|
Dee Estuary |
Cheshire / Clwyd |
Y |
|
13,679.7 |
33,803.3 |
SJ220800 |
1954 |
|
Breckland Farmland |
Norfolk / Suffolk |
Y |
|
13,335.7 |
32,953.2 |
TL762783 |
2000 |
|
North Dartmoor |
Devon |
Y |
Y |
13,413.2 |
33,144.7 |
SX580850 |
1952 |
|
North Exmoor |
Devon / Somerset |
Y |
Y |
12,005.3 |
29,665.7 |
SS800430 |
1954 |
|
Sites more than 4000 hectares in size
Site name |
Area of Search |
Reason for designation |
Area[ a] |
Grid reference |
Year in which notified |
Map[B] |
Biological interest |
Geological interest |
Hectares |
Acres |
South Dartmoor |
Devon |
Y |
Y |
9,668.2 |
23,890.6 |
SX630690 |
1952 |
|
Hexhamshire Moors |
County Durham / Northumberland |
Y |
|
9,433.9 |
23,311.7 |
NY870530 |
1998 |
Map |
Kielderhead and Emblehope Moors |
Northumberland |
Y |
|
8,254.4 |
20,397.1 |
NT700000 |
1971 |
|
Eastern Peak District Moors |
South Yorkshire / ? |
Y |
Y |
8,094.4 |
20,001.7 |
SK270770 |
1955 |
Map |
Bollihope, Pikestone, Eggleston and Woodland Fells |
County Durham |
Y |
|
7,949.2 |
19,642.9 |
NZ005300 |
1996 |
Map |
North Norfolk Coast |
Norfolk |
Y |
Y |
7,700.0 |
19,027.1 |
TG020440 |
1954 |
|
Mersey Estuary |
Cheshire / Merseyside |
Y |
|
6,702.1 |
16,561.2 |
SJ440800 |
1951 |
|
The Swale |
Kent |
Y |
Y |
6,568.4 |
16,230.9 |
TR000670 |
1968 |
|
Blackwater Estuary |
Essex |
Y |
Y |
5,738.0 |
14,178.9 |
TL940070 |
1955 |
|
South Thames Estuary and Marshes |
Kent |
Y |
|
5,449.1 |
13,465.0 |
TQ770785 |
1951 |
|
Bodmin Moor, North |
Cornwall |
Y |
|
4,957.0 |
12,249.0 |
SX160810 |
1951 |
|
Kielder Mires |
Cumbria / Northumberland |
Y |
|
4,818.0 |
11,905.5 |
NY670800 |
1995 |
|
Bowes Moor |
County Durham |
Y |
|
4,457.7 |
11,015.2 |
NY923104 |
1989 |
Map |
Poole Harbour |
Dorset |
Y |
|
4,049.0 |
10,005.3 |
SZ000890 |
1964 |
|
Sites more than 2000 hectares in size
Site name |
Area of Search |
Reason for designation |
Area[ a] |
Grid reference |
Year in which notified |
Map[B] |
Biological interest |
Geological interest |
Hectares |
Acres |
Chichester Harbour |
Hampshire / West Sussex |
Y |
Y |
3,695.0 |
9,130.5 |
SU760000 |
1970 |
|
Bridgwater Bay |
Somerset |
Y |
|
3,574.1 |
8,831.8 |
ST290480 |
1989 |
|
Dungeness |
East Sussex / Kent |
Y |
Y |
3,241.7 |
8,010.4 |
TR050180 |
1951 |
|
Ashdown Forest |
East Sussex |
Y |
|
3,144.6 |
7,770.5 |
TQ450300 |
1953 |
|
South Exmoor |
Devon / Somerset |
Y |
|
3,132.7 |
7,741.1 |
SS880340 |
1992 |
|
Long Mynd |
Shropshire |
Y |
Y |
2,637.6 |
6,517.7 |
SO420950 |
1953 |
|
Alde-Ore Estuary |
Suffolk |
Y |
|
2,554.3 |
6,311.8 |
TM394757 |
1952 |
|
The Quantocks |
Somerset |
Y |
|
2,506.9 |
6,194.7 |
ST140390 |
1970 |
Map |
Ouse Washes |
Cambridgeshire / Norfolk |
Y |
|
2,403.0 |
5,937.9 |
TL482867 |
1955 |
|
Exe Estuary |
Devon |
Y |
Y |
2,186.6 |
5,403.2 |
SX980845 |
1952 |
|
East Dartmoor |
Devon |
Y |
Y |
2,088.1 |
5,159.8 |
SX695815 |
1976 |
|
Langstone Harbour |
Hampshire |
Y |
|
2,069.4 |
5,113.6 |
SU700030 |
1958 |
|
Sites more than 1500 hectares in size
Site name |
Area of Search |
Reason for designation |
Area[ a] |
Grid reference |
Year in which notified |
Map[B] |
Biological interest |
Geological interest |
Hectares |
Acres |
Thorne Crowle and Goole Moors |
East Riding / South Yorkshire |
Y |
|
1,918.6 |
4,741.0 |
SE730160 |
1970 |
|
Windsor Forest and Great Park |
Berkshire / Surrey |
Y |
|
1,771.2 |
4,376.7 |
SU970685 |
1973 |
|
Exmoor Coastal Heaths |
Somerset |
Y |
|
1,758.3 |
4,344.9 |
SS620480 |
1994 |
Map |
Wyre Forest |
Shropshire / Hereford & Worcester |
Y |
|
1,753.7 |
4,333.5 |
SS750760 |
1955 |
|
Epping Forest |
Essex / Greater London |
Y |
|
1,728.0 |
4,270.0 |
TL475035 |
1953 |
|
Porton Down |
Wiltshire |
Y |
|
1,561.8 |
3,859.3 |
SU240365 |
1977 |
Map |
Rutland Water |
Leicestershire |
Y |
|
1,540.1 |
3,805.7 |
SK928070 |
1981 |
|
Sites more than 1000 hectares in size
Site name |
Area of Search |
Reason for designation |
Area[ a] |
Grid reference |
Year in which notified |
Map[B] |
Biological interest |
Geological interest |
Hectares |
Acres |
Upper Severn Estuary |
Gloucestershire |
Y |
|
1,436.8 |
3,550.4 |
SO720060 |
1954 |
Map |
Tamar - Tavy Estuary |
Cornwall / Devon |
Y |
|
1,422.3 |
3,514.6 |
SX474650 |
1991 |
|
Hatfield Moors |
South Yorkshire |
Y |
|
1,400.7 |
3,461.2 |
SE705060 |
1954 |
|
Avon Valley (Bickton to Christchurch) |
Dorset / Hampshire |
Y |
|
1,383.7 |
3,419.2 |
TU147123 |
1974 |
|
Braunton Burrows |
Devon |
Y |
Y |
1,356.7 |
3,352.5 |
SS430350 |
1952 |
|
Taw-Torridge Estuary |
Devon |
Y |
|
1,336.5 |
3,302.6 |
SS470310 |
1981 |
|
Nene Washes |
Cambridgeshire |
Y |
|
1,310.0 |
3,237.1 |
TL200977 |
1959 |
|
Portsmouth Harbour |
Hampshire |
Y |
|
1,266.1 |
3,128.6 |
SU620035 |
1974 |
|
East Devon Pebblebed Heaths |
Devon |
Y |
|
1,111.9 |
2,747.6 |
SY050880 |
1952 |
|
Catcott, Edington and Chilton Moors |
Somerset |
Y |
|
1,083.0 |
2,676.2 |
ST390420 |
1967 |
Map |
West Sedgemoor |
Somerset |
Y |
|
1,016.0 |
2,510.6 |
ST361258 |
1983 |
Map |
Haldon Forest |
Devon |
Y |
|
1,013.2 |
2,503.7 |
SX886838 |
1992 |
Map |
Sites more than 750 hectares in size
Site name |
Area of Search |
Reason for designation |
Area[ a] |
Grid reference |
Year in which notified |
Map[B] |
Biological interest |
Geological interest |
Hectares |
Acres |
Chesil and the Fleet |
Dorset |
Y |
Y |
990.4 |
2,447.3 |
SY496885 |
1952 |
|
Fenn's, Whixall, Bettisfield, Wem and Cadney Mosses |
Shropshire / Wales |
Y |
|
948.4 |
2,343.5 |
SJ490365 |
1953 |
|
Tealham and Tadham Moors |
Somerset |
Y |
|
917.6 |
2,267.4 |
ST420450 |
1985 |
Map |
Savernake Forest |
Wiltshire |
Y |
|
904.7 |
2,235.6 |
SU215665 |
1971 |
Map |
King's Sedgemoor |
Somerset |
Y |
|
822.0 |
2,031.2 |
ST400330 |
1985 |
|
Grafham Water |
Cambridgeshire |
Y |
|
811.9 |
2,006.2 |
TL150680 |
1986 |
|
Durham Coast |
Cleveland / Durham |
Y |
Y |
765.4 |
1,891.3 |
NZ400500 |
1960 |
|
Rye Harbour |
East Sussex |
Y |
Y |
761.1 |
1,880.7 |
TQ935180 |
1953 |
Map |
Studland and Godlingston Heath |
Dorset |
Y |
Y |
758.9 |
1,875.3 |
SZ030845 |
1954 |
|
Sites more than 500 hectares in size
Site name |
Area of Search |
Reason for designation |
Area[ a] |
Grid reference |
Year in which notified |
Map[B] |
Biological interest |
Geological interest |
Hectares |
Acres |
Blue Anchor to Lilstock Coast |
Somerset |
|
Y |
742.8 |
1,835.5 |
ST033435 |
1971 |
|
Abberton Reservoir |
Essex |
Y |
|
716.3 |
1,770.0 |
TL970180 |
1955 |
|
Lynher Estuary |
Cornwall |
Y |
|
687.3 |
1,698.4 |
SX375565 |
1951 |
|
North Moor |
Somerset |
Y |
|
676.3 |
1,671.2 |
ST325305 |
1986 |
|
Cotswold Commons And Beechwoods |
Gloucestershire |
Y |
|
665.5 |
1,644.5 |
SP900130 |
1954 |
Map |
Bentley Wood |
Wiltshire / Hampshire |
Y |
|
665.0 |
1,643.3 |
SU250295 |
1985 |
Map |
Barle Valley |
Somerset |
Y |
|
622.9 |
1,539.2 |
SS850349 |
1954 |
|
Pagham Harbour |
Avon |
Y |
Y |
615.9 |
1,521.9 |
SZ875970 |
1954 |
|
Upper Fal estuary and woodlands |
Cornwall |
Y |
|
603.5 |
1,491.3 |
SW850410 |
1968 |
|
Chew Valley Lake |
Avon |
Y |
|
565.2 |
1,396.6 |
ST570600 |
1971 |
|
Arne |
Dorset |
Y |
Y |
563.4 |
1,392.2 |
ST966880 |
1986 |
|
Westhay Moor |
Somerset |
Y |
|
513.7 |
1,269.4 |
ST455445 |
1971 |
Map |
Breydon Water |
Norfolk |
Y |
|
506.5 |
1,251.6 |
TG500075 |
1987 |
Map |
Sites more than 400 hectares in size
Sites more than 300 hectares in size
Sites more than 250 hectares in size
Sites more than 200 hectares in size
Sites more than 150 hectares in size
Sites more than 100 hectares in size
Notes
- a Data rounded to one decimal place.
- B Link to maps using the Nature on the Map service provided by English Nature.