A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

Holding the current title of "biggest chair in the world," it stands with little fanfare in Lucena, Spain.

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

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

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

The bones of two medieval royal lions were discovered at the historic fortress.

This ancient Egyptian obelisk still bears the wounds of World War I.

The commemorative stone column conceals a secret laboratory.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

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

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

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

Eighty million natural history specimens call this gargantuan museum home.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

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

An old trolley bridge was converted into a breathtaking garden bursting with colorful flowers.

"the sweltering inhabitants of Charleston and New Orleans, of Madras and Bombay and Calcutta, drink at my well . . . The pure Walden water is mingled with the sacred water of the Ganges."

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.