A tribute to a Ukrainian heroine who went undercover and killed several Nazi operatives.

A subterranean Holocaust refuge within one of the world's longest cave systems.

One of the most poignant ruins of the Chernobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

This ancient fortress in Iran was once the oldest and largest treasury in the world.

In this tiny Iranian town playing on the roof isn't just encouraged, it's the only place to go.

One of the largest and oldest caravansaries in Persia.

This ruined fortress was the stronghold for a persecuted medieval leader and his infamous Assassins.

Iran's colorful terraces are a rare geological masterpiece.

Putrefaction plateaus in Iran, where the dead were sent for decontamination before going to their final resting place.

Like something out of a bad acid trip, this Ukraine hallway has been covered in hallucinatory phantasmagoria.

This underground transport hub doubles as an art gallery.

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

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

A Kyiv-based repository for all manners of discarded curiosities.

The deepest metro station in the world.

A city entirely devoted to illegal gun production.

A slice of central Asia in the middle of Berlin.

This massive library holds what was once the largest book collection in the world.

A monument to Lenin has been transformed into a statue of everyone's favorite black-helmeted, fool-choking Sith Lord.

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

Legions of Roman soldiers bathed in this ancient spa complex under a Budapest transit station.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

These picturesque structures speckle the hill above the monastery.