An homage to the medieval rulers of Bulgaria.

A decaying, yet still functioning, work of communist architecture.

The temple that withstood the Nazis.

A gigantic statue of a Russian soldier watches over the ancient city of Plovdiv, a prominent reminder of the Soviet period in Bulgaria.

A magnificent, glittering building tucked into a tiny Bulgarian mountain town.

A striking symbol of the Bulgarian capital.

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

An abandoned saucer-shaped monument in the Bulgarian mountains.

Mysterious standing stone formations looks like a petrified forest.

This hauntingly beautiful cemetery outside a medieval citadel is full of winding paths and ivy-covered graves.

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

This massive underground salt mine now holds a sci-fi theme park in its depths.

Museum devoted to the artificial language of Esperanto.

Handsomely crafted representations of our round planet.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

The final resting place for the remains of 143 Habsburg royalty.

The beautiful baroque library of the Hapsburg empire.

A marble Lucifer hides behind the pulpit of this Gothic cathedral.

This vast masterpiece of Moroccan architecture spreads across 20 acres.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

Perched above the bustling town of Kerak is a sprawling, ruinous castle that has witnessed nearly a millennia of Levantine history.

Known as the "Valley of the Moon," this Jordanian wadi is one of the most amazing desertscapes on Earth.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.