Northern Europe’s largest castle ruins sit precariously on an island cliffside.

The ruins of a 15th-century castle that has seen its fair share of bitter feuds.

The remains of a 13th-century stronghold built by the Welsh prince known as Llywelyn the Last.

This remote location of this Moorish stronghold means it doesn’t attract many tourists—and that it still has the aura of fear and bravery of the 1300s.

A rare example of an ancient Japanese hill castle believed to be the fortress of a legendary demon.

A seaside castle complex that stood through centuries of conquests.

The little-known second castle that William the Conqueror built in York.

Ruins of a 13th-century fortress perched above a breathtaking Mediterranean bay.