The final resting place of the poets Shelley and Keats.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

The underground sanctuary of a mysterious ancient cult.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

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

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

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

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

Submerged ruins of a Neolithic coastal settlement, where houses, wells, graves and skeletons have been unearthed.

This marvelous work of outsider architecture is built into the cliffs of an Israeli beach.

A sprawling ancient Jewish cemetery with over 30 rock-hewn burial caves.

It took a lifetime to collect these mechanical musical wonders.

Built by a king and rebuilt by an emperor, this aqueduct transported water for 1,200 years to this ancient Mediterranean hub.

An ancient underground cultic temple where sunlight penetrates on the summer solstice.

Mysterious face-like images that appeared within an Andalusian house are surrounded by legends of the paranormal.