This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

Visit a surreal landscape so otherworldly NASA actually used it to train the Apollo 17 crew.

This 18th-century sundial was designed to calculate the date of Easter each year.

This pub built its reputation pouring post-shift pints for employees of the cemetery with which it shares a wall.

William Blake claimed to have painted this gothic masterpiece after encountering this nightmarish being in a vision.

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

An oddly conical beacon perched atop beautiful Irish cliffs.

The remains of Crystal Palace Great Exhibition of 1851.

Shakespeare, David Bowie, Dr. Who, the Saxons, Druids and Romans are all claimed to have all made their mark on these massive man made tunnels.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

A kaleidoscopic warehouse-maze of handmade neon signs.

Lyon's miniature version of the Eiffel Tower was built as a statement in support of French secularism.

The eclectic observatory castle of a 19th-century astronomer and explorer.

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

These stark white cliffs were spat up by the sea and are slowly being retaken by it.

The tomb of history's greatest potato promoter is surrounded by tubers.

Original cabaret handbills, posters, and feline artwork are a purrfect highlight of the Museum of Montmartre.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

This museum in a Paris apartment gives a unique look at the iconic French singer's life.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

BDSM, 1930s Style.

Beggars were miraculously "cured" of their fake ailments when they returned home to this 17th century Paris slum each night.

A modern-day Lascaux cave underneath Paris.