The tallest mountain in mainland Netherlands isn't actually very tall.

Incredible labyrinth of man made caves.

This sprawling Belgian fort was once thought of as impenetrable but now it is simply an abandoned relic.

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

Crouch down, stretch tall, and be sure to flail your legs to pay homage to the Monty Python classic.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

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

This historical Netherlands fortress still bears the marks of its single siege.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.