Remnants of the city's Soviet history hover over this modern fast-food outlet.

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

Gargantuan home of Russian science.

Legends of time travel and magical woodland creatures bolster the natural charm of this verdant sanctuary in the midst of Moscow.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

Moscow's other, lesser known kremlin is a fairytale-like cultural complex modeled after Old Russia.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

The current seat of the Parliament of Andalusia was once the epicenter of the Great Plague of Seville.

Hidden behind a wall, Spanish nuns distribute their signature sweets on a revolving tray.

The final resting place of the great navigator, or maybe his brother.

The world's largest wooden structure.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This curious, round temple is the oldest still-standing marble building in Rome.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

An alchemist's "magic door" stands in the middle of a Roman park.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

This castle has links to Portugal’s founding and struggles for independence.

Ancient catacombs form the foundation for this Rococo orgy of a church.