• The grass-covered earth mound which dates from William the conquerors reign

• The stone keep that was built on the orders of Henry III in the mid-thirteenth century

• The gatehouse that was erected in the seventeenth century to replace an earlier entrance

The English Heritage guide book gives a brief summary:

Clifford’s Tower is the central strong-hold of York Castle.  The castle was first built by William the Conqueror to secure his hold on the north of England.  It featured earthwork defences, a timber tower on top of the mound or motte, and domestic buildings in the courtyard (now occupied by the law courts and museum).  Over a century after its construction, in 1190, the Jews of York took refuge from a murderous mob in this tower.  This tragic episode ended in their mass suicide, during which the tower was consumed by flames.

It was rebuilt in stone by Henry III between 1245 and 1272, and has since survived floods, fire and partial destruction.  Little now remains, however, of the curtain walls, towers and gates of the courtyard or outer bailey.