Castle Acre Castle and town walls are a set of ruined medieval defences built in the village of Castle Acre, Norfolk. The castle was built soon after the Norman Conquest by William de Warenne, the Earl of Surrey, at the intersection of the River Nar and the Peddars Way. William constructed a motte-and-bailey castle during the 1070s, protected by large earthwork ramparts, with a large country house in the centre of the motte. Soon after, a small community of Cluniac monks were given the castle's chapel in the outer bailey; under William, the second earl, the order was given land and estates to establish Castle Acre Priory alongside the castle. A deer park was created nearby for hunting.