The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Eighty million natural history specimens call this gargantuan museum home.

Hear the quietest sound from across the dome.

A medieval replica of King Arthur's legendary table, the Round Table hanging in Winchester Castle was decorated by Henry VIII.

This ruined medieval castle was the scene of Lord Robert Dudley’s seductive reception for Queen Elizabeth I.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

A lush indoor jungle fills this bustling Madrid transportation hub.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

Turntable anonymously received orphans, alms, and groceries.

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

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

This cemetery features modernist statues as strange as its name.

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

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

Love, knishes, and best wishes from this legendary Lower East Side bakery.

The oldest surviving synagogue in New York City is now a soaring art space.

Elevated freight railway turned wildly successful urban park.

You'll find just about anything in this funky Tbilisi flea market.

Despite being tiny and rural this Georgian airport looks like a sci-fi boondoggle.

A museum glorifying the life of Stalin, located in the city of his birth.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

Unusual building appears to be haphazardly built from randomly piled bricks.