Marston Thrift

Marston Thrift is a 37.4 hectare biological Site of Special Scientific Interest between Marston Moretaine and Cranfield in Bedfordshire. It was notified in 1984 under Section 28 of the Wildlife and Countryside Act 1981, and the local planning authority is Central Bedfordshire Council. It is also a Local Nature Reserve, which extends to a larger area of 55.8 hectares.

The site is ash and maple woodland on heavy clay, a habitat which has become scarce in lowland England. It also has areas of damp grassland, and a grassland valley. It is an important site for butterflies, including the rare black hairstreak.

There is access from a car park at Wood End, and by footpaths from Cranfield and Marston Moretaine.