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

Rebuilt several decades ago, its striking murals prevent it from being reconsecrated as a church.

An homage to the medieval rulers of Bulgaria.

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.

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

This historic black and white monastery is one of Bulgaria's architectural jewels.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

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.

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.

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

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

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

An industrial site turned into Hungary's most cherished natural wonder.

This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.

Hidden on the urban banks of a Manchester river are a series of abandoned waterside industrial sites.

A stretch of land where the sour-sweet vegetable is cloaked in darkness and grows so fast you can hear it crack, squeak, and pop.