4f4c4942-4343-5764-6473-3938373736 English Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-04-07T15:48:16.608Z NRW 1.0 wel British National Grid (EPSG::27700) Sites of Special Scientific Interest (SSSIs) Sites of Special Scientific Interest (SSSIs) Safleoedd o Ddiddordeb Gwyddonol Arbennig (SoDdGA) Sites of Special Scientific Interest (SSSI).lyr Sites (SSSI) 2026-04-01 NRW_DS98776 This spatial dataset contains the digital boundaries of Sites of Special Scientific Interest (SSSIs) in Wales. SSSIs cover a wide range of habitats from small fens, bogs and riverside meadows to sand-dunes, woodlands and vast tracts of uplands. Most are in private ownership, although some are owned and managed by local wildlife trusts, or other voluntary conservation bodies. Notification of an SSSI under the Wildlife and Countryside Act 1981 has since been amended by the Countryside and Rights of Way Act 2001, which brought about numerous changes in the way SSSI are notified managed and protected. In order to ensure consistent, favourable long-term management of these sites, Natural Resources Wales (NRW) with landowners have prepared management plans for all SSSI in Wales. Local planning authorities are required to consult NRW before allowing any development to proceed that may affect an SSSI. Water, gas and electricity companies must also do the same. SSSIs have been designated, from 1949 to the present day, and are on-going. The data has been held digitally since the mid-1990s. This data has been checked by relevant NRW staff. Please refer to the designation map as the legal definitive boundary. For large SSSIs that were captured digitally and have been printed on a smaller scale map than OS MasterMap, please refer to the OS MasterMap edition at time of capture to view the definitive boundary. This spatial dataset contains the digital boundaries of Sites of Special Scientific Interest (SSSIs) in Wales. SSSIs cover a wide range of habitats from small fens, bogs and riverside meadows to sand-dunes, woodlands and vast tracts of uplands. Most are in private ownership, although some are owned and managed by local wildlife trusts, or other voluntary conservation bodies. Notification of an SSSI under the Wildlife and Countryside Act 1981 has since been amended by the Countryside and Rights of Way Act 2001, which brought about numerous changes in the way SSSI are notified managed and protected. In order to ensure consistent, favourable long-term management of these sites, Natural Resources Wales (NRW) with landowners have prepared management plans for all SSSI in Wales. Local planning authorities are required to consult NRW before allowing any development to proceed that may affect an SSSI. Water, gas and electricity companies must also do the same. SSSIs have been designated, from 1949 to the present day, and are on-going. The data has been held digitally since the mid-1990s. This data has been checked by relevant NRW staff. Please refer to the designation map as the legal definitive boundary. For large SSSIs that were captured digitally and have been printed on a smaller scale map than OS MasterMap, please refer to the OS MasterMap edition at time of capture to view the definitive boundary. Mae'r set ddata ofodol hon yn cynnwys ffiniau Safleoedd o Ddiddordeb Gwyddonol Arbennig (SoDdGA) yng Nghymru. Mae SoDdGA yn cwmpasu amrywiaeth eang o gynefinoedd megis ffeniau bach, corsydd, dolydd glan afon, twyni tywod, coetiroedd ac ardaloedd helaeth o ucheldir. Mae'r rhan fwyaf mewn perchnogaeth breifat, er bod rhai yn eiddo i ac yn cael eu rheoli gan ymddiriedolaethau bywyd gwyllt lleol neu gyrff cadwraeth gwirfoddol eraill. Mae dynodiad SoDdGA dan Ddeddf Bywyd Gwyllt a Chefn Gwlad 1981 wedi ei ddiwygio gan Ddeddf Cefn Gwlad a Hawliau Tramwy 2001, a gyflwynodd newidiadau niferus i'r ffordd y mae SoDdGA yn cael eu dynodi, eu rheoli a'u gwarchod. Er mwyn sicrhau bod rheolaeth hirdymor yr ardaloedd hyn yn gyson a ffafriol mae Cyfaeth Naturiol Cymru, ar y cyd thirfeddianwyr, wedi paratoi cynlluniau rheoli ar gyfer pob SoDdGA yng Nghymru. Mae'n ofynnol i awdurdodau cynllunio lleol ymgynghori â CNC cyn caniatáu i unrhyw ddatblygiad fynd rhagddo a allai effeithio ar SoDdGA. Mae'n rhaid i gwmnau dŵr, nwy a thrydan wneud hynny hefyd. Mae SoDdGA wedi cael eu dynodi dros nifer o flynyddoedd, o 1949 hyd heddiw, ac maent yn parhau. Datganiad priodoli Yn cynnwys gwybodaeth Cyfoeth Naturiol Cymru © Cyfoeth Naturiol Cymru a Hawl Cronfa Ddata. Cedwir pob hawl. Yn cynnwys data Arolwg Ordnans. Rhif Trwydded Arolwg Ordnans AC0000849444. Hawlfraint y Goron a Hawl Cronfa Ddata. Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Protected sites GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme conservation (see also conservation of specific subjects) Site of Special Scientific Interest (SSSI) habitats (see also specific types of habitats) geographical information systems (GIS) NRW Thesaurus 2026-03-04 geonetwork.thesaurus.local.theme.converted_nrw-keywords Habitat extent Habitat characterisation SeaDataNet Parameter Discovery Vocabulary 2024-06-19 geonetwork.thesaurus.external.theme.rdf+xml Mountains, Moorland and Heaths (SMNR) Provisioning Services (SMNR) Regulating Services (SMNR) Ecosystem (SMNR) Animals, Plants and Other Organisms (SMNR) Sea and Coast (SMNR) Marine (SMNR) Freshwater and Wetlands (SMNR) Semi-natural Grasslands (SMNR) Management Areas (SMNR) Cultural Services (SMNR) Woodlands (SMNR) Physical Geography (Physiography) (SMNR) Coastal Margins (SMNR) Sustainable Management of Natural Resources (SMNR) Ecosystem Services (SMNR) Natural Resources (Incl. Features and Processes) (SMNR) Soil and Land (SMNR) NRW SMNR Keywords 2024-06-26 geonetwork.thesaurus.local.theme.converted_nrw-smnr-keywords There are no access restrictions on this data. NRW may release, publish or disseminate it freely. no limitations © CNC/NRW All rights Reserved. Contains Ordnance Survey Data. Ordnance Survey Licence number AC0000849444. Crown Copyright and Database Right Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and copyright of the owners. It is the recipient's responsibility to ensure the data is fit for the intended purpose. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Contains Ordnance Survey Data. Ordnance Survey Licence number AC0000849444. Crown Copyright and Database Right. Open Government Licence English biota environment imageryBaseMapsEarthCover geoscientificInformation Wales (WLS) -5.777741 -2.608865 51.240829 53.513067 SeaVoX Vertical Co-ordinate Coverages 2013-02-05 creation inapplicable 1992-01-01 Please refer to Countryside Acts 1949,1981 and 2001, for reasons for capture of original designation. NRW has also created a subset of this dataset showing only those where relate to the marine environment. These are available on the Welsh Government marine planning portal. Geographic Information System ESRI Feature Class https://datamap.gov.wales/layers/inspire-nrw:NRW_SSSI WWW:LINK-1.0-http--link Download Data and Web Service https://datamap.gov.wales/capabilities/layer/386/?ows_service=wms OGC:WMS Web Mapping Service Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false All SSSIs designated before GIS technology have been converted into digital data from paper maps of various scales. In 2008 the whole dataset was updated to OS MasterMap (mostly to CCW 2006 OS update). This update referred to the original designation maps and all notational descriptions on these maps e.g. “Only the water under the bridges included in the site” OR “SSSI boundary follows, in part the lines of the Mean High and Low Water Marks; both are liable to change.” All new or re-notified sites will be put to the latest release by NRW of OS MasterMap and this information is recorded in the attribute data under the Last_Edited column. As OSMM is updated by the Ordnance Survey it is important to check where boundaries may subsequently have moved. All SSSIs designated before GIS technology have been converted into digital data from paper maps of various scales. In 2008 the whole dataset was updated to OS MasterMap (mostly to CCW 2006 OS update). This update referred to the original designation maps and all notational descriptions on these maps e.g. “Only the water under the bridges included in the site” OR “SSSI boundary follows, in part the lines of the Mean High and Low Water Marks; both are liable to change.” All new or re-notified sites will be put to the latest release by NRW of OS MasterMap and this information is recorded in the attribute data under the Last_Edited column. As OSMM is updated by the Ordnance Survey it is important to check where boundaries may subsequently have moved.