A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

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

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.

This demon atop the Notre-Dame de Paris looks utterly bored.

The industrial architecture honors the laborers who brought the Exposition Universelle of 1900 to life.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

The commemorative stone column conceals a secret laboratory.

Revel in the Victorian splendor of the world's oldest eating establishment inside a museum.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

Scattered throughout London are ancient remnants of the city's former bounding wall.

One part local history, 99 parts gruesome haunted house.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

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

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A semi-scholarly approach to sex.

Elevated freight railway turned wildly successful urban park.

A terrific purveyor of natural history objects and curios.

A colorful square marks the heart of the city's LGBTQ community.