As a general rule, place names in London start out as designations which cover a large area. They are then additionally peppered with points such as the names of farms, wells, mills and taverns. Through the process of densification, smaller areas become nominalised until the original name covers a much smaller area. For instance, an area once bordering Sydenham, Penge Common and South Norwood is now called Crystal Palace after the entertainment complex was transferred to Sydenham from Hyde Park. The north western part of Sydenham become rebranded as Forest Hill at the very end of the C18th as indicated by an advert in The Times for new houses. Consequently, what was Sydeham in Tudor times has gradually shrunk to accomodate it's edges developing their own local character.
Westwood House was set back from Westwood Hill and the first owner Mr.Ximenes got the Lord of the Manor of Lewisham to agree to plant a grove of elms leading up to his mansion which is now the road called Jews Walk.
Sydenham Common was a 500 acre mix of heath, scrub and pasture at the geographic heart of historic Sydenham. It was on the eastern side of Sydenham Hill which runs south west to north east along a ridge 100m above sea level. Consequently the Common was tipping rainwater gently down toward the River Pool. As such, the Common had several rivulets which had been tamed by ditches and agricultural ponds. This explains why the canal company sited a large reservoir on the common as it intercepted these hillside streams to keep it topped up. This in turn kept the Croydon Canal topped up. When the reservoir was drained and auctioned in plots, the printer Robert Harrild acquired the plot in the area west of the canal and around what is now Albion Millennium Green.