Scarborough Castle is situated on a roughly triangular headland that rises 300ft above the sea. There is evidence of Iron Age settlements and the remains of a Roman signal station on the site, but the first mediaeval castle was built by William le Gros, Count of Aumale, in the 1130's. He constructed a wall on the landward side of the promontory and built a tower where the keep now stands. When Henry II came to the throne in 1154 he demanded the return of all royal castles, and Scarborough, which was built on a royal manor, was one of the castles reclaimed by the Crown.