Porton Down SSSI is a biological Site of Special Scientific Interest which spans the border between

Hampshire Hampshire (, ; abbreviated to Hants) is a ceremonial county, ceremonial and non-metropolitan county, non-metropolitan counties of England, county in western South East England on the coast of the English Channel. Home to two major English citi ...

and

Wiltshire Wiltshire (; abbreviated Wilts) is a historic and ceremonial county in South West England with an area of . It is landlocked and borders the counties of Dorset to the southwest, Somerset to the west, Hampshire to the southeast, Gloucestershir ...

in England. It is adjacent to

Porton Down Porton Down is a science park in Wiltshire, England, just northeast of the village of Porton, near Salisbury. It is home to two British government facilities: a site of the Ministry of Defence's Defence Science and Technology Laboratory (Dstl) ...

science park near

Porton Porton is a village in the Bourne valley, Wiltshire, England, about northeast of Salisbury. It is the largest settlement in Idmiston civil parish. The village gives its name to the nearby Porton Down military science park, which is home to t ...

, and much of it is

Ministry of Defence {{unsourced, date=February 2021 A ministry of defence or defense (see spelling differences), also known as a department of defence or defense, is an often-used name for the part of a government responsible for matters of defence, found in state ...

property which is closed to the public. It is a Nature Conservation Review site, Grade I, a

Special Area of Conservation A Special Area of Conservation (SAC) is defined in the European Union's Habitats Directive (92/43/EEC), also known as the ''Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora''. They are to protect the 220 habitats and a ...

and a

Special Protection Area A Special Protection Area (SPA) is a designation under the European Union Directive on the Conservation of Wild Birds. Under the Directive, Member States of the European Union (EU) have a duty to safeguard the habitats of migratory birds and cert ...

. This is one of the largest areas of semi-natural chalk grassland in the country. It has also been designated an SSSI because of its important populations of lichens,

vascular plant Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They ...

s and invertebrates, and for its breeding

stone curlew The stone-curlews, also known as dikkops or thick-knees, consist of 10 species within the family Burhinidae, and are found throughout the tropical and temperate parts of the world, with two or more species occurring in some areas of Africa, Asia, ...

s. There are also areas of scrub and woodland.

References

{{SSSIs Wilts biological Sites of Special Scientific Interest in Hampshire Sites of Special Scientific Interest in Wiltshire