Most of it is heathland and dry acid grassland on the Blackheath Pebble Beds.

[2] It is only two miles from Charles Darwin's home, Down House, and he often visited to study the plants and animals there.

It helped to provide the materials for his works on earthworms and carnivorous plants.

'Darwin's Landscape Laboratory', which included Keston Common, was the British Government's 2009 nominee for a World Heritage Site, but the application was unsuccessful.

[2] The common is a Site of Metropolitan Importance for Nature Conservation and an Area of Archaeological Significance with earthworks which are a listed structure.