added by archaeologs A 12th-century castle built by Richard the Lion-Heart on his return from the Third Crusade in 1196. Sitting on the Andelys cliff overlooking the Seine River in France, substantial portions of it still stand. Château Gaillard, the strongest castle of its age, guarded the Seine River valley approach to Normandy. It was successfully besieged by Philip II in 1204. The French isolated the fort with a double ditch, then collapsed part of the châtelet and penetrated the main fortress through the latrines.