An underground city of salt.

Poland's oldest salt mine has nearly everything one needs to live underground forever.

Former headquarters of the KGB.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

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

This newly renovated Soviet-era outdoor exhibition center is bigger than the principality of Monaco.

Moscow's imposing monument to the Space Age.

Museum celebrating the achievements of the Soviet space program.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.

The past, present, and future of Russia's signature alcohol is remembered in the world's only museum dedicated to the starchy spirit.

The largest bottled beer collection in the world holds over 22,000 unique beer bottles.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

Copenhagen's celebrated theme park and gardens.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

No one knows who's responsible for decorating this tunnel with stuffed animals, but the people love it enough to protest their removal.

The world's first ice hotel is still one of the most elaborate and beautiful.

Across the Pacific in a raft, a museum dedicated to Thor Heyerdahl's now legendary expedition.

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

Home to three historic ships from the age of Vikings.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

St George's Leprosy Museum depicts the gruesome afflictions of those suffering from the disease.

A favorite with sightseers, this Norwegian funicular provides easy access to a stunning view of Bergen and its environs.