This 15th-century cave complex is one of the very few monasteries to stay open throughout World War II and the Soviet regime.

This towering statue of Jesus provided internet to the surrounding area.

The world's only silo that was topped by two revolving restaurants has unfortunately been demolished.

Fantastic views and thousands of love locks.

The entrance to this Frankfurt subway station looks like an old tram car crashed into the concrete sidewalk.

Revitalization efforts converted a former U.S. military heliport into a sprawling urban park.

Historic slum of Tartu.

An iconic Soviet statue of working-class people.

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

Thirteen sculptures in central Moscow graphically depicting vices of the modern world.

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

Stalinist skyscraper built with help of cryotechnology.

Gargantuan home of Russian science.

A small part of Russia that does not touch any other part of Russia.

This monument commemorates the soldiers who fought for 16 hours straight to penetrate this concrete fort.

The reason for the strange contortions in the trunks of these "drunken" pine trees in Russia is still a mystery.

These tiny cabins on a cableway have been carrying visitors at a Baltic resort down to the beach since 1912.

Where Stoddart and Connolly suffered in the infamous Bug Pit.

This "tower of death" has acted as an observatory, a religious hub, and an executioner's lair.