Archaeological site Old Sarum in Wiltshire

You're standing on Old Sarum, a bare hilltop about two miles north of Salisbury. This is where the city first began. Look around at those huge earth banks. They were dug around 400 BC, in the Iron Age. The fort is oval, roughly four hundred metres long, with a double bank and a ditch in between, and its entrance on the east side. Whoever held this hill controlled two trade routes and the River Avon.