In 1068-9, William the Conqueror built two motte and bailey castles in York, to strengthen his military hold on the north. Clifford's Tower, an unusual four-lobed keep built in the 13th century atop the mound of William's larger fortress, is now the principal surviving stonework remnant of York's medieval castle.
The sweeping views of the city from the tower still show why it played such an important part in controlling northern England. The tower has a turbulent history, surviving 1,000 years of flood, fire and siege. Its origins were violent: William the Conqueror built the castle for his northern campaign of terror in 1069.