This cubist Vienna church building looks like some sort of alien stonehenge.

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

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Museum devoted to the artificial language of Esperanto.

This former insane asylum now holds a pathological anatomy museum.

Dine amidst exotic plants at this former royal greenhouse.

The social hall of this former factory is a Communist-era time capsule.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

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

The Grand Mall in Varna hosts one of the biggest collections of Soviet-era paraphernalia in Bulgaria.

Sofia's legislative center is continuously reinventing itself.

This massive stone and steel monument remembers a century-old battle that cost thousands of lives and nearly destroyed the city.

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

A mysterious tunnel hidden in the shadows of a colorful, historic sanctuary.

Ruins of an early Roman Christian church dating back to the 4th to 5th centuries.

Eastern Bloc nostalgia, anybody?

"Unity, Creativity, Beauty."

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

Outstanding, eerie frescoes and decorations fill this 19th-century monastery.

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.

A collection of art from Bulgaria's time as a communist state.

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

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