In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Built over an abandoned train yard, this hidden gem is full of winding paths and offers gorgeous views of Sydney Harbour.

The Netherlands' first car tunnel has an unusually rectangular shape.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

Wind power station for making famous Ketel One vodka.

An idyllic hotel that gave its name to a supposed shadow government.

This historic Dutch newspaper building is covered with media-themed details—and one unrelated oddity.

Rotterdammers' dirty minds gave this Santa a dirty nickname and cursed it to a life of wandering.

Scale model of St. Peter's Cathedral (Rome) in the middle of a small Dutch town.

The largest 19th century panorama in the world still in-situ.

Yup, that's a 330-foot yacht passing over the highway.

Its town washed away centuries ago, this lonely tower by the sea tells the tale of a mermaid and a curse.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

A miniature city, once ruled by the Queen of the Netherlands.

A seven-century-old jail tells a not-so-pleasant history of crime and punishment.

Amsterdam's former hotspot for public executions and dissections.

A grassy pyramid named after a French battle.

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

The Bloemen Route, or “Flower Route”, stretches 25 miles through prime Dutch tulip country as a result of “tulip mania,” the world’s first economic bubble.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

Romania's triumphal arch looks out over Bucharest.