A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle of Man. SSSI/ASSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in the United Kingdom are based upon them, including national nature reserves, Ramsar sites, Special Protection Areas, and Special Areas of Conservation. The acronym "SSSI" is often pronounced "triple-S I".
The geology of Wales is complex and varied; its study has been of considerable historical significance in the development of geology as a science. All geological periods from the Cryogenian to the Jurassic are represented at outcrop, whilst younger sedimentary rocks occur beneath the seas immediately off the Welsh coast. The effects of two mountain-building episodes have left their mark in the faulting and folding of much of the Palaeozoic rock sequence. Superficial deposits and landforms created during the present Quaternary period by water and ice are also plentiful and contribute to a remarkably diverse landscape of mountains, hills and coastal plains.
Allt Penycoed Stream Section is a Site of Special Scientific Interest in Carmarthenshire, Wales. It is protected by law and has been designated as an SSSI since April 1985 in an attempt to protect rare or unique features or species within it. The site has an area of 1.62 hectares and is managed by Natural Resources Wales.
Crûg Farm Quarry is a Site of Special Scientific Interest (SSSI) in Carmarthenshire, Wales, for the geological records preserved in its limestone.
Cleeve Common is a 455-hectare (1,120-acre) biological and geological Site of Special Scientific Interest in Gloucestershire, England, notified in 1974. It is looked after by a small charity called Cleeve Common Trust, formally Cleeve Common Board of Conservators.
Arfordir Abereiddi is a Site of Special Scientific Interest (SSSI) in Pembrokeshire, South Wales. It has been designated as a Site of Special Scientific Interest since January 2002 in an attempt to protect its fragile biological and geological elements. The site has an area of 63.74 hectares and is managed by Natural Resources Wales.
Cwm Dewi is a Site of Special Scientific Interest in Pembrokeshire, South Wales. It has been designated as a Site of Special Scientific Interest since January 2010 in an attempt to protect its important geological elements. The site has an area of 22.02 hectares and is managed by Natural Resources Wales.
Dwrhyd Pit is a Site of Special Scientific Interest in Pembrokeshire, South Wales. It has been designated as a Site of Special Scientific Interest since January 1957 in an attempt to protect its fragile geological elements. The site has an area of 0.18 hectares and is managed by Natural Resources Wales.
Robeston Wathen Quarries is a Site of Special Scientific Interest in Pembrokeshire, South Wales, immediately to the north of the village of Robeston Wathen. It has been designated as a Site of Special Scientific Interest since January 1967 in an attempt to protect its fragile geological elements. The site has an area of 1.64 hectares and is managed by Natural Resources Wales.
Stackpole Quay - Trewent Point is a cliff on the Castlemartin Peninsula of South Pembrokeshire, South Wales and is a Site of Special Scientific Interest (SSSI). It has been designated as a SSSI since January 1977 in an attempt to protect its fragile biological and geological elements. The site has an area of 64.15 hectares and is managed by Natural Resources Wales.
Strumble Head - Llechdafad Cliffs is a Site of Special Scientific Interest (SSSI) in Pembrokeshire, South Wales. It has been designated as a SSSI since January 1954 in an attempt to protect its fragile biological and geological elements.
Treffgarne Bridge Quarry is a Site of Special Scientific Interest in Pembrokeshire, South Wales. It has been designated as a Site of Special Scientific Interest since January 1954 in an attempt to protect its fragile geological elements. The site has an area of 0.4 hectares and is managed by Natural Resources Wales. The name derives from the Welsh "Trefgarn".
Cors Bodwrog is a mesotrophic mire and a Site of Special Scientific Interest in Anglesey, North Wales. It has been designated as a Site of Special Scientific Interest since January 1961 in an attempt to protect its fragile biological elements. The site has an area of 87.28 hectares and is managed by Natural Resources Wales.
Glannau Penmon - Biwmares is a Site of Special Scientific Interest in Anglesey, North Wales. It has been designated as a Site of Special Scientific Interest since January 1957 in an attempt to protect its fragile biological and geological elements. The site has an area of 170.87 hectares and is managed by Natural Resources Wales.
Glannau Rhoscolyn is a Site of Special Scientific Interest in Anglesey, North Wales, and extends along the west coast of Holy Island, Anglesey for approximately 6.5 km (4.0 mi). It has been designated as a Site of Special Scientific Interest since January 1961 in an attempt to protect its fragile biological and geological elements. The site has an area of 145.49 hectares and is managed by Natural Resources Wales.
Henborth is a Site of Special Scientific Interest in Anglesey, North Wales. It has been designated as a Site of Special Scientific Interest since October 1989 in an attempt to protect its fragile geological elements. The site has an area of 10.96 hectares and is managed by Natural Resources Wales.
Llanbadrig - Dinas Gynfor is a Site of Special Scientific Interest in Anglesey, North Wales. It has been designated as a Site of Special Scientific Interest since January 1957 in an attempt to protect its fragile geological elements. The site has an area of 26.49 hectares and is managed by Natural Resources Wales.
Llyn Bodgylched is a Site of Special Scientific Interest in Anglesey, North Wales, to the west of Beaumaris. It has been designated as a Site of Special Scientific Interest since January 1968 in an attempt to protect its fragile biological elements, mainly a swamp. The site has an area of 16.37 hectares and is managed by Natural Resources Wales.
Afon Seiont is a Site of Special Scientific Interest in West Gwynedd, Wales. It is protected by law and has been designated as a Site of Special Scientific Interest since July 1997 in an attempt to protect rare or unique features or species within it. The site has an area of 6.4 hectares and is managed by Natural Resources Wales. This site is designated due to its geological qualities. In Wales, geological sites range from quarries to rocky outcrops and massive sea-cliffs. 30% of SSSIs in Wales are notified for geological and geomorphological features.
This article describes the geology of the Brecon Beacons National Park in mid/south Wales. The area gained national park status in 1957 with the designated area of 1,344 km2 (519 sq mi) including mountain massifs to both the east and west of the Brecon Beacons proper. The geology of the national park consists of a thick succession of sedimentary rocks laid down from the late Ordovician through the Silurian and Devonian to the late Carboniferous period. The rock sequence most closely associated with the park is the Old Red Sandstone from which most of its mountains are formed. The older parts of the succession, in the northwest, were folded and faulted during the Caledonian orogeny. Further faulting and folding, particularly in the south of the park is associated with the Variscan orogeny.
