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

The ornate miniature mansions were built for Istanbul's feathered residents.

A marvel of Byzantine engineering under the streets of Istanbul.

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

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

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.

Dedicated to the European Sinti and Roma peoples murdered during the Holocaust.

Berlin's beloved bear is immortalized at the Museum für Naturkunde.

At one of Berlin’s oldest churches, visitors can place mosaic tiles to help restore a medieval mural.

One of the world's heaviest musical instruments towers within a popular urban park.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

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

The most visited, and possibly most controversial, museum in Germany.

A plaque bearing the names of those who dedicated themselves to protecting Budapest's Jewish population during World War II.

A triumphant marble and bronze fountain depicting a 15th-century Hungarian king and his hunting party.

The metal leaves on this tree are engraved with the names of Holocaust victims.

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

Time stands still at this serene burial ground in the center of Budapest.

A fake Transylvanian castle houses a cathedral of antlers.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.