A self-proclaimed libertarian micro-state on a tiny bit of disputed territory between Serbia and Croatia.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

These warring psychedelic crags commemorate an unsuccessful military operation.

Yugoslavia's biggest underground airport lies in ruins.

A subterranean playground in an abandoned slate mine.

In this mine all the gold you can carry may not be as sweet of a deal as it sounds.

Ireland's only German military cemetery holds the remains of a spy who was moved there under the cover of darkness.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

Local legend says the remains of Father Christmas lie within the medieval grounds.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

Once the longest bridge in Ireland, this rusting span sits abandoned and overrun by nature.