A centuries-old forgotten underworld lies beneath Malta.

A shining memorial to a Belgian hero is said to bring luck to anyone who touches it.

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

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

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

"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.

One of the oldest wine cellars in Germany is now a restaurant beneath Bremen's town hall.

A spitting ode to a German serial killer.

A stunning gilt bronze relief denounced by Hitler as "degenerate art"—even though it was dedicated to the Nazi leader.

Böttcherstraße's bells, extolling Nordic virtues and the great conquerors of the world.

The only remaining U-boat that is still floating never actually saw any action in World War II.

This restored eighth-century palace is a shining example of ancient Umayyad architecture.

An oasis of shade and color amidst the bustle of the old city.

This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

The world's oldest map of the holy land gives us a fragmented glimpse of the layout of biblical nations.

The most gigantic, swoony, intimidating trio of fingers in all of antiquity.

An ancient capital city that dates back 3,000 years and harbors many surprises.

This collection of solar timekeepers includes the world's first digital sundial.

This bike path was sunk below water level for maximum wonder.

Amidst medieval and baroque buildings, five human-sized gherkins stand tall.