The Forest extends over 424 hectares, including Wall Wood and Woodside Green. It has been designated a Site of Special Scientific Interest and a National Nature Reserve. It is located in northwest Essex, and is an oasis in a landscape dominated by agriculture, M11 and Stansted Airport.

The ecology is in notably pristine condition, only little affected by recent and destructive land use practices, making it one of the largest areas of land in East Anglia which has not been ploughed in historical times. These habitats provide a direct link and continuity with the primeval vegetation cover of Britain and its invertebrate inhabitants.

The ancient coppices and wood pasture are likely to be managed relics of the original wildwood and are now extremely rare providing a last refuge for much rare and specialized wildlife, including dead-wood beetles and fungi, hole-nesting birds and bats, which also have a requirement for unimproved pasture.

The ancient trees, often in excess of 600 years old, created by traditional management practices, are like magnificent living sculptures, peaceful giants worn and fragile from centuries of seasons and use. They encompass much of what is significant about the Forest and each is unique both in shape and in the ecosystem it supports.