 Redhill Common, now partly built on at St John's, is on the Greensand Ridge.The Redhill Brook runs through the town, mainly culverted, and upstream to the immediate north-east of the town are The Moors nature reserve and the large 2010–2012 (mid and low-rise) Watercolour housing development, comprising 25 acres (10 ha) of lakes, paths and wildlife habitat managed by the Surrey Wildlife Trust.The brook enters a culvert behind Redhill station and briefly reappears at Halford's car park.