Photo ©Malcolm Butler

Chateau des Marais, or Ivy Castle as it is also known, is a motte and bailey that was probably constructed in the 12th century on a rocky hillock surrounded by marshes. The fort fell into disuse after it was superseded by Castle Cornet which was built in the mid 13th-century. It was refortified at the end of the 18th century when the stone fort on the site was constructed, the ditch was re-cut, musket firing steps were added around the outer bailey and the inner bailey was walled in. During the German occupation of the island, a command bunker was constructed inside the walls and machine gun posts were also built.