 The resulting castle was huge, protected on one side by the sea cliffs, with a stone curtain wall, a massive gatehouse and six towers around the outside.A harbour was built on the south side of the fortress, enabling access from the sea.Northumbria was a lawless region in this period, suffering from the activities of thieves and "schavaldours", a type of border brigand, many of whom were members of Edward II's household, and the harbour may have represented a safer way to reach the castle than land routes.