The largest Roman amphitheater in the Balkans once held over 20,000 people, but managed to lay hidden for hundreds of years.

One of the most photographed locations in the entire city.

These abundant, over-the-top monuments are so widely scattered that they define the entire compact capital cityscape, often leading to jokes about whether there are more statues than residents.

Artists made this mosque into a marvel of Ottoman baroque architecture.

This fortress dates back to the 6th century and is also the site of a controversial abandoned restoration project.

Sofia's legislative center is continuously reinventing itself.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Tiny memorials honor individual victims of the Holocaust.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

Museum dedicated to the UK's first charity for abandoned children, with keepsakes of the mothers who left them behind.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

An unfinished Serbian Orthodox church with 1,389 golden crosses planned to represent the Battle of Kosovo.

This massive monument was unveiled the day Kosovo declared independence from Serbia.

Christianity and Islam have clashed, yet here a Serbian Orthodox church and a mosque stand together.

A 11-foot former president stands on a Kosovo street that also bears his name.

A futuristic, brutalist masterpiece that is also strangely prison-like.

A symbol of hope, survival, and national character, especially after it rose phoenix like from the flames.

A former royal garden with lush surroundings in the heart of the city.

Legend says it was constructed with the destroyed pillar of an ancient Greek Temple.

One of the newest mosques in a city filled with thousands.

The home-turned-museum of Barış Manço, the mustachioed Turkish Elvis for children.

Ancient serpentine sacrifice holder that has stood the test of time.

Large miniature theme park with 100-plus models.