Swift's Hill (grid reference SO877067) is a 9.15-hectare (22.6-acre) biological and geological Site of Special Scientific Interest in Gloucestershire, notified in 1966 and renotified in 1984.

A small stock-holding field (semi-improved pasture) was purchased for the trust by Swift Print of Stroud in 1989.

[3] The hill is one of the smaller ancient Cotswold Commons and provides panoramic views of the Slad valley which is described by local author Laurie Lee in Cider with Rosie.

Fossil-rich 'ragstones' are exposed and is one of the key sites for study of the geology of the Middle Jurassic period.

[4] The thin, well-drained Rendzina soils supports a diverse range of calcareous grassland flora.

The grassland flora supports good populations of small blue, green hairstreak, dingy skipper and marbled white butterflies.

The reserve is open year-round, with the best visiting period from April to August, offering opportunities to observe its vibrant biodiversity.