Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

This abandoned bridge to nowhere stands secluded in the woods of a Cleveland suburb.

Monty Python fans will recognize this abandoned mine as the Cave of the Killer Rabbit of Caerbannog.

This weird abode has inspired everything from the "House On Haunted Hil" to a robot hunter's pad.

After 800 years, Europe's oldest elm tree has met its end.

This small memorial honors a ferocious feline and local hero.

A huge old mansion full of thousands of toys, each there to be used and played with.

A shining memorial to a Belgian hero is said to bring luck to anyone who touches it.

Head underground and take a tour of the city's working sewer system, and see the underground river Senne, which defined Brussels for centuries before being covered in the 19th century.

Climb inside an iron crystal magnified 165 billion times its normal size.

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

Medical history with an amazing, if frighting, collection of wax diseases on display.

Meet the bronze beloved pet to a family of famous peeing statues.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

Theme park featuring miniature replicas of European monuments.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

Lavish royal estate punctuated with heated greenhouses.

An incarceration museum on the spot of possibly the oldest prison in England.

If it hadn't been caught in time, a flaw in the design of this Manhattan skyscraper could have led to its collapse.

Once a safe haven for locals engaged in blood feuds, this 400-year-old fortified tower is now a museum showing what life was like for those lying in wait within its walls.

Spend the night in this formerly abandoned traditional Scottish village.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

Colin Stokes "got a bit carried away" and built a castle that looks like something out of Tolkien.

A tribute to the incredible generosity the Choctaw Nation showed the Irish people during the Great Famine.