The second largest in the world, this massive underground void has its own subway.

A museum glorifying the life of Stalin, located in the city of his birth.

The cave holds a spectacular array of stalactites and stalagmites, including one shaped like a giant human heart.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

The secret room where early Bolsheviks cranked out propaganda fliers on a smuggled printing press.

A small but hugely whimsical theater where marionettes play out the "The Battle of Stalingrad."

Luxury hotel turned into a refugee camp, then turned back into a luxury hotel.

This neon lit Georgian cave claims to hold the boulder Prometheus was chained to.

These Stalin-era industrial 'death traps' hang lifeless above the city

Unusual building appears to be haphazardly built from randomly piled bricks.

The first skyscraper to include a Ferris wheel built into the facade.

You'll find just about anything in this funky Tbilisi flea market.

Fast food feels like fine dining at this award-winning modern Georgian building.

A literally moving statue of stacked metal giants just continually trying (and failing) to find love.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

Cycling around the Veluwe visitors are treated to a collection of stones from around the world.

Rejoice at Amsterdam's ‘pop temple,’ a former church reborn as a raucous music venue.

An independent cinema housed in a former pathological anatomy laboratory.

A family-run botanical garden with tropical plants, artsy sculptures, and eccentric buildings.

The only bicycle museum in the Netherlands charts the invention of the now-ubiquitous two-wheeled machine.

Various sculptures are a rotating exhibit in this small town.

Some of the specimens on display at the Leiden University Medical Center have been helping educate physicians since the 17th century.

A solid steel plane designed to catch fire over and over again.

At this barrel organ museum, history and live concert keep Dutch street organ culture alive.