 Also nearby are Whitewebbs Park and Clay Hill House.The hill which gives its name to the district lies to the north of the built-up area and is mainly occupied by Forty Hall and its grounds.It rises to a plateau around above sea level composed of the Boyn Hill Gravel, a deposit laid down by the River Lea approximately 400,000 years ago, when that river lay further to the west, and at a higher altitude than it does today.