Sydenham Hill Wood is a nine-hectare wood on the northern slopes of the Norwood Ridge in the London Borough of Southwark. It is designated as a Local Nature Reserve and Site of Metropolitan Importance for Nature Conservation. With the adjacent Dulwich Wood, Sydenham Hill Wood is the largest extant tract of the ancientGreat North Wood. The two woods were separated after the relocation of The Crystal Palace in 1854 and the creation of the high level line in 1865.
The land is owned by the Dulwich Estate, leased to Southwark Council, who lease Sydenham Hill Wood and Cox's Walk to London Wildlife Trust. Sydenham Hill Wood and Fern Bank are a Local Nature Reserve.
In 1997 Sydenham Hill Wood was given the UK-MAB Urban Wildlife Award for Excellence. There are conservation workdays and wildlife events.
The oak-lined formal avenue, known as Cox's Walk, leading from the junction of Dulwich Common and Lordship Lane was cut soon after 1732 by Francis Cox to connect his Green Man Tavern and Dulwich Wells with the more popular Sydenham Wells. When the poet Thomas Campbell lived in Sydenham (between 1805 and 1822) he visited his friend Dr Glennie, in Dulwich Grove. After the relocation of the Crystal Palace in 1854, the Dulwich Estate made plots along Sydenham Hill available on long leases, and a series of large houses was built. Between the junction with Crescent Wood Road and Cox's Walk there were seven houses. One of the largest was The Hoo, standing almost opposite the present 36 Sydenham Hill.