Roughdown Common, part of the Box Moor Trust Estate, is a chalk hill which dominates the south side of Hemel Hempstead and is one of Hertfordshire's few remaining examples of unimproved chalk grassland. There used to be a large quarry here. If you look carefully you can find an old entrance to a mine shaft. These days the old mine workings provide a safe place for bats to roost and hibernate.
The common is accessed via a number of well-trodden footpaths used regularly by dog walkers. There are some benches that allow visitors to relax and take in the views.
Roughdown Common is orchid-rich and home to many rare species of wild plants and insects. In 1953 the area was designated as a SSSI (Site of Special Scientific Interest). The common with its chalk grassland flora boasts a shrub species unique to this type of habitat which is a wild juniper, a small conifer, the berries of which are used to flavour distilled spirit gin.
The navvies who constructed the Grand Union Canal lived in encampments, one of which was on Roughdown Common.
Car parking can be found in some nearby roads.