This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

This colorful gate stands as an entrance to the walled city of Old San Juan.

The bat-covered home of one of the world's most popular brands of rum is located on a tropical Art Deco campus.

This tiny home was originally a narrow alleyway.

This chapel on a cliff is renowned for its healing powers and was founded on the site of a supposed divine intervention.

A park where people have been going to feed friendly pigeons since the 18th century

Erotic art covers the walls of the largest ancient pleasure palace.

The walls and streets of the ancient city are peppered with penises.

Ancient snack bar of the Roman Empire re-opened.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

The mystic whose incorrupt corpse still attracts the faithful.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

An oasis of beauty, tranquility and botanical research in the middle of Rome.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

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

A massive marble foot is tucked away in a small alley near the Pantheon.

In Rome’s Jewish ghetto, a 200-year-old bakery still makes the neighborhood’s historic sweets.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.