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

Take respite inside this jaw-dropping church while climbing the volcano where Georgia's Prometheus was once chained.

Replica of mosque destroyed by Russia in the 16th century.

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

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

340-foot statue built to honour the Heroes of the Soviet Union.

Marvel at the excessive luxury of the ousted Ukrainian president's former estate.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

This derelict superstructure was a very important warning system for the Soviet military.

The dining hall that nourishes workers in Chornobyl's Exclusion Zone is also open to visitors.

This pirate-broadcasting-tower-turned-restaurant played a rebellious role in the history of Dutch television.

The deepest metro station in the world.

Kyiv's answer to Muscle Beach is a Soviet-era gym made from scrap metal.

This abandoned church in central Lyon is missing its front stairs.

Lyon's "Wall of the Silk Weavers" is one of the largest murals in Europe.

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

Moscow's imposing monument to the Space Age.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

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

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

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

The site of the first battle of World War II.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

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