A Site of Special Scientific Interest (SSSI) is a designated area in the United Kingdom recognized for its unique natural features, wildlife, or geological importance. These sites are protected to conserve their special characteristics and ensure that they remain intact for future generations. SSSIs can include a variety of habitats, such as wetlands, woodlands, and coastal areas. The designation of an SSSI is managed by organizations like Natural England in England and Natural Resources Wales in Wales. Activities that could harm the site are regulated, and landowners may need to follow specific guidelines to maintain the ecological balance and biodiversity of the area.