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

A marvel of Byzantine engineering under the streets of Istanbul.

Ride in 1960s style on the private luxury train Marshal Josip Tito used to travel around Yugoslavia.

These warring psychedelic crags commemorate an unsuccessful military operation.

An abandoned monument remembering the "Pančevo Holocaust" now stands as a shadow of its former self.

1513 Turkish world map, full of European state secrets and snarky commentary.

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

It houses the remains of a 17th-century version of the Titanic.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

Stone age urban planning.

In the hinterlands of Serbia's capital, a giant reflective mushroom houses an aeronautical history of the former Yugoslav republic.

A misnamed well, with a deep dark past.

Curious carved stones and bird-like wings are a symbol of Serbian resilience and freedom on the site of a WWII massacre.

Abstract monuments express sorrow and resilience at the site of a horrific massacre in Nazi-occupied Serbia.

Religious perseverance and cultural coexistence manifest in an architectural gem that multiple wars couldn't topple.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

This spaceship-like Serbian monument reaches for the stars in celebration of the fallen fighters of fascism.

Structure built from the skulls of vanquished foes.

One of the most controversial statues in Romania is an emperor with no clothes.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

This snug medieval lane is one of the narrowest streets in the world.

The bust of Romania’s most notorious ruler, Vlad Dracula aka "Vlad the Impaler," keeps watch over the ruins of his medieval court.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."