Main Quarry or Castle Hill Quarry is a 14.7 hectares (36 acres) geological Site of Special Scientific Interest in Mountsorrel in Leicestershire.[1][2] It is a Geological Conservation Review site.[3]
According to Natural England, this site "is probably the most dramatic and well-developed occurrence of asphaltite in Britain upon which international research into the origin of life on Earth has been carried out."[4]
The site is private land with no public access.
52°43′37″N 1°08′49″W / 52.727°N 1.147°W / 52.727; -1.147