The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

This Italian-style temple replica has been threatening to fall off the Irish coast for hundreds of years.

These murals stand as reminders to the troubled history of this Northern Ireland city.

This cemetery overlooking the Benbulben rock formation is the final resting place of one of Ireland's most beloved poets.

Originally built to monitor fishing, this Victorian tower now educates visitors about the local salmon industry.

The Guardian of Tallinn.

Only a fragment of this 15th-century Dance of Death survives today.

This medieval Estonian tower provides access to a series of tunnels that have been home to soldiers, punks, and fine art.

"There's nothing there," and other lies the KGB told us.

This endearingly discomfited urinating statue commemorates the sneaky pees had by us all.

This irregularly shaped sea fortress has defended not one but three different sovereign states.

An alien church provides much needed silence in the midst of a Finland shopping center.

A subterranean house of worship carved right out of the bedrock.

A unique seaside cave where Aleister Crowley faked his own death.

Picturesque intersection of witchcraft and ancient Christianity.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.