An ancient Egyptian temple in the middle of Madrid, Spain.

A Serbian church lit by chandeliers made of weapons.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

A misnamed well, with a deep dark past.

A pair of connected skyscrapers form this symbolic gateway.

Structure built from the skulls of vanquished foes.

Sofia's legislative center is continuously reinventing itself.

An homage to the medieval rulers of Bulgaria.

A vast Communist-era exhibition space in the Bulgarian capital.

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

A mountain pass in Bulgaria's Balkan Mountains was the site of four historic battles.

"Holy Wisdom" overlooks the city that became its namesake.

"Unity, Creativity, Beauty."

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

A striking symbol of the Bulgarian capital.

The site of many battles and tragedies, including the 40 maidens who leapt into the sea.

A flamboyant five-story building in Bulgaria resembles a crawling snail.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

The ceiling of Prohodna Cave in northern Bulgaria affords a peek at the sky via two deity-sized-eye-shaped holes.

This historic black and white monastery is one of Bulgaria's architectural jewels.

Bizarrely shaped rock formations in northwest Bulgaria come with equally bizarre legends.