A decommissioned submarine base makes a great space for graffiti art.

Mysterious craters may have been home to an ancient cult.

Cold war icon and onetime "hole" in the iron curtain.

Roughly 17 million letters to Santa have found their way to this Arctic Circle post office.

An abstract monument to a symphonic composer.

This endearingly discomfited urinating statue commemorates the sneaky pees had by us all.

A subterranean house of worship carved right out of the bedrock.

A traditional U-Bahn station in Berlin gets a string of rather untraditional benches.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This modest marker near Notre Dame identifies the very center of Paris.

France's most famous cemetery, with some of its most curious tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

Sweden's "good old days" painstakingly re-created in a model village.

It houses the remains of a 17th-century version of the Titanic.

Eighty million natural history specimens call this gargantuan museum home.

A peculiarly shaped brass sculpture hidden in a courtyard in central Lviv

One of the world’s best microminiaturist, Nicolaï Siadristy displays his lifetime of tiny creations in this museum.

The haunting complex honors the millions of Ukrainians who died in the forced famine under Soviet rule.

This 1000 year old relic-filled cave monastery and UNESCO World Heritage Site also hosts an amazing micro-miniature museum.

An Art Nouveau building covered in animal gargoyles and grotesques.

One of the largest museums in Ukraine remembers the story of the German-Soviet War in iconic, brutalist style.

When you've got to go, you've got to go.

The deepest metro station in the world.