Rochester Castle in Medway

You're standing at Rochester Castle, on the bank of the River Medway. Look up at that huge square tower. This is the twelfth-century keep, and it's the tallest in England. The corner turrets rise to about 125 feet. Archbishop William de Corbeil built it after King Henry I granted him the castle in 1127. The cathedral is right next door, because church and castle belonged together here.