Long abandoned underground complex to keep royals safe from a nuclear war that never came.

Tiny effigies of the victims of Edinburgh's famous Anatomy Murders.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

This bird-loving brewery is situated in an old municipal bathhouse, nestled beside a 300-year-old windmill.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

The largest collection of handbags in the world, the oldest of which were used to carry Bibles, primarily by men.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

A floating cat sanctuary on an Amsterdam canal.

A stunning Victorian abbey and walled garden on a lakefront.

Though they've since been renamed, these two streets hint at Dublin's darker days.

This Irish museum in a historic 19th century market pays tribute to the glory of butter.

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

The "feral child" who appeared in Bavaria in the 19th century remains as much a mystery as his unsolved murder.

This magnificent museum claims to house the cranium of a disciple and the skull of a pope.

The abandoned remains of this Victorian brewery hide crumbling bowling alleys and rusting industrial gear.

A brush maker used his factory to protect blind Jews from the Gestapo.

These brass bunnies honor the rabbits that dominated the no-man's-land around the Berlin Wall.

Hundreds of hidden passageways weave through the old quarters of Lyon.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.