An iconic red telephone box turned tiny art gallery.

Ride the subways of yesteryear.

This 700-year-old structure is one of the most unique architectural and historic monuments in Gdańsk.

A vintage penny arcade hidden in the back of a fun fair-themed bar.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

A former top secret nuclear fallout shelter now operates like a hotel stuck in the Cold War.

A 19th century library favored by Edgar Allan Poe and H.P. Lovecraft, known by locals as "the Ath."

The bridges portrayed on EU currency aren't fictional anymore.

This 1920s Dutch barge is now a floating bookstore.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

This Russian locomotive museum was once devoted just to Lenin's funeral before expanding to encompass Moscow's entire train history.

The majority of the museum's large collection is held in a storage space open to the public a few times a year.

An Oxford museum where visitors can have tea with the Mad Hatter and climb through the wardrobe to a fantasy land.

They call buildings like this "mimetic architecture," but nothing has ever mimicked the taste of Moxie.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Storage warehouse of the rich and famous.

Created hundreds of years ago, the magical follies and landscapes at this park were almost lost to time before being restored.

The pits used to load the nuclear bombs onto the aircraft that dropped them over Hiroshima and Nagasaki at the end of World War II.

Cannon designed to fire an atomic warhead.

The sculpture is made of more than 100,000 knives collected to raise awareness about violence.

Remnants of a cone-shaped Nazi bomb shelter.

A unique Holocaust memorial tells the personal stories of the Jewish residents exiled from greater Berlin.

The Isle of Wight’s “Island Line” serviced by former London Underground trains from the 1930s.