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

In the hometown of the Catholic saint and Nobel Peace Prize winner, a memorial dedicated to her legacy.

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

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

A fountain standing as a testament to a doomed alliance.

An Art Nouveau gem hides beneath the layers of city grime obscuring this once-magnificent building.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

Sofia's legislative center is continuously reinventing itself.

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

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

A striking symbol of the Bulgarian capital.

17th century palace once a meeting place for politicians.

Romania's triumphal arch looks out over Bucharest.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This once-derelict building is now one of the most beautiful bookstores in the world.

A collection of items from a way of life that no longer exists.

A diminutive statue that was inspired by the sculptor's own daughter.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.