Pleshey Castle dominates the picturesque village of Pleshey in Essex, six miles northwest of Chelmsford, with one of the largest motte-and-bailey earthworks in Great Britain. Built in the late 11th century following the Norman Conquest, this impressive castle was granted by William the Conqueror to Geoffrey de Mandeville, who established his seat and administrative center here. The original 50-foot-high motte once supported a stone keep, with additional protection from inner and outer baileys surrounded by deep ditches and moats. A brick bridge dating to the 1450s still crosses the motte moat, surviving intact when most buildings were demolished by the 1600s for construction material. The castle's remarkable medieval earthworks remain a testament to Norman military engineering and are now open by appointment only.