Aldbury Nowers is a 19.7 hectare biological Site of Special Scientific Interest (SSSI) in Dacorum, in Hertfordshire. The site was notified in 1990 under the Wildlife and Countryside Act 1981. It is managed by the Hertfordshire and Middlesex Wildlife Trust. The site, formerly known as "Duchie's Piece," comprises two areas of hillside, linked by The Ridgeway. The site hosts the flowers of chalk grassland and has butterfly habitats with several different species of butterfly including the Duke of Burgundy, hairstreaks and the Essex skipper.