Enormous - according to English Heritage equivalent to 50 football pitches - Iron Age hillfort with multiple and complex ramparts and ditches. This was ancient Dorchester! Here, Vespasian's highly trained Roman troops overcame the British defenders, the Durotriges tribe, one of whom ended up with a ballista in his spine. There's not much to see, but quite a lot to marvel and wonder at.
Photo by Major George Allen (1891–1940) (Ashmolean Museum) via Wikimedia Commons