A Cold War command center is hidden under an idyllic countryside.

This bike path was sunk below water level for maximum wonder.

A rare example of World War I trenches from the British front.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

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

Housing the famous Norwegian ice-defying 19th century polar exploration ship.

The design of this beautifully crafted building was inspired by Norwegian glaciers.

Home to three historic ships from the age of Vikings.

This courtly monument celebrates an influential comedian who turned taking the piss out of the powers-that-be into an art.

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This Slovenian museum houses the country's largest collection of painted beehive panels.

A public work of art that also provides some relief from the summer heat.

The costumes depict the Kurent, the star character of the annual Kurentovanje festival.

A trough of 700 strange bronze faces runs through a narrow alley in Ljubljana's old town.

Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

A whimsical bridge adorned with decorative dragons.

A miniature train-ride through Slovenia's largest cave system.

This massive subterranean fissure is known as the "underground Grand Canyon."

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

This panoramic lift provides a futuristic ride up San Pedro Mountain.

This 47-story "M" needed 20 years to be completed

Catalonia Tradition: Beating the hollow Christmas log until it defecates in your fireplace.

This postmodern apartment block was designed to be a vertical neighborhood.