The hill is the summit of the uppermost or eastern ridge of the Norwood Ridge which in turn was for several millennia covered by the Great North Wood but sits on thin topsoil. In the 19th century Sydenham Hill became a fashionable area, with a large number of large residential properties built along Sydenham Hill, including Grange Court (1861), The Wood (1840), Dilkhoosh (now Fountain House) (1864), Highfield (1855), The Cedars (1894), Sydenham Hill House (1898), Dulwich Wood House (1858), Beltwood House (1851) and Castlebar (1879). The writer Joseph Ashby-Sterry was born into a Sydenham Hill family in 1836 or 1838. In 1854, the area's importance was increased after the Crystal Palace was relocated from Hyde Park and re-erected on the south-western end of the ridge.