The county has a long history of human settlement and some notable archaeology, such as the hill forts of Maiden Castle, Badbury Rings and Hod Hill. A large defensive ditch, Bokerley Dyke, delayed the Saxon conquest of Dorset for up to 150 years. There are numerous ancient burial sites and standing stones. Some of the more impressive include the stone circles at Kingston Russell, Hampton Hill, Rempstone and Nine Stones near Winterbourne Abbas. Just north of Portesham is a huge Neolithic dolmen known as the Hell Stone consisting of nine upright stones and a capstone.