The earthwork remains of Sandal Castle stand on a low hill in the village of Sandal Magna, a couple of miles south of Wakefield. The motte and bailey were thrown up in the early twelfth century by William de Warenne, second Earl of Surrey; the stone keep that crowned them was added in the thirteenth century and stayed in use until the Civil War, when Parliamentarian forces dismantled it to prevent its reuse.
Today the site is a public park, with interpretive panels explaining the layout and a small visitor centre attached. The views are excellent — the castle was sited deliberately to overlook the river crossing and the road south. Combine the visit with a meal in one of the village pubs.