Epping Forest is a 2,400-hectare (5,900-acre) area of ancient woodland, and other established habitats, which straddles the border between Greater London and Essex. The main body of the forest stretches from Epping in the north, to Chingford on the edge of the London built-up area. South of Chingford the forest narrows, and forms a green corridor that extends deep into East London, as far as Forest Gate; the forest's position gives rise to its nickname, the Cockney Paradise. It is the largest forest in London.

In the United Kingdom, ancient woodland is that which has existed continuously since 1600 in England, Wales and Northern Ireland. Planting of woodland was uncommon before those dates, so a wood present in 1600 is likely to have developed naturally.