The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

The last resting place of the famous Native American princess is marked by a haunting monument.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

This foreboding medieval castle was twice besieged by barons rebelling against the English king.

The Neolithic megalith was one of the first archaeological ruins protected by the British government.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

This former abandoned hospital, a complex of stunning 19th century buildings, once housed 2,000 psychiatric patients.