Sofia's legislative center is continuously reinventing itself.

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

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

"Unity, Creativity, Beauty."

Eastern Bloc nostalgia, anybody?

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

UNESCO-protected ancient burial ground.

A striking symbol of the Bulgarian capital.

An ancient Thracian city where fire rituals were practiced on the largest cult altar in Southeast Europe.

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

An abandoned saucer-shaped monument in the Bulgarian mountains.

Elevated freight railway turned wildly successful urban park.

The most confusing clock in New York.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Gargantuan home of Russian science.

The tallest hotel in Europe.

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

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

The second oldest continuously operating bar in Louisiana.

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