Eat your way through history.

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

Taking the subway here means doing so over a bridge located in the middle of an estuary.

This museum was invented in a novel before being made real by the author.

This historic hotel preserves many treasures from its heyday hosting passengers on the Orient Express.

Housed in an old British jail, this spot serves up Georgian, Russian, and Ukrainian specialities with a side of Turkish history.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

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

A surprising and unconventional mosque hidden in the subsoil of Istanbul.

A massive cave once a secret military base is now home to thousands of bats.

A spectacular Bulgarian cave resembling a devil's head with a waterfall rushing down its throat.

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

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

An interactive museum-like experience takes visitors back to 1980s Communist Bulgaria.

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

Sofia's legislative center is continuously reinventing itself.

This building has two facades of clashing architectural designs.

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

A striking symbol of the Bulgarian capital.

Eastern Bloc nostalgia, anybody?

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

Locals believe this abandoned ruin on the outskirts of Bucharest is haunted.

A chemical factory damaged by two earthquakes and an explosion that became abandoned after bankruptcy.

After sitting unused for decades, this abandoned communist infrastructure became a wildlife utopia.