site of special scientific interest

In the UK, land that has been identified as having animals, plants, or geological features that need to be protected and conserved. From 1991 these sites were designated and administered by English Nature, Scottish Natural Heritage, and the Countryside Council for Wales.

Numbers fluctuate, but Britain had almost 5,000 SSSIs in 1998, two-thirds of which were privately owned. Although SSSIs enjoy some legal protection, this does not in practice always prevent damage or destruction; during 1992, for example, 40% of SSSIs were damaged by development, farming, public access, and neglect. A report by English Nature estimated that a quarter of the total area of SSSIs, over 1 million acres, had been damaged by acid rain. Around 1% of SSSIs are irreparably damaged each year. In 1995–96 7% of Welsh SSSIs and 4.2% of English SSSIs experienced damage.

In September 1998 the British government proposed to pay compensation to landowners only if they undertake to properly manage these sights.