A historic observatory precariously perched at the "Top of Europe."

A Nesting Doll of Churches.

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

This ancient market is often referred to as the oldest shopping mall in the world.

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

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

An ancient Roman temple first dedicated to an emperor's wife is now a church.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

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

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

This curious, round temple is the oldest still-standing marble building in Rome.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

A diverse collection of wax, bone, papier-maché and mummified relics.

One of the longest wooden benches in the world snakes around Geneva's Treille Promenade.

An unlikely Transcendental Meditation haven in the American Heartland built around the ancient Vedic principles of balance and harmony.

A collection of oddities including Dr. Kevorkian's suicide device, the Thanatron.

A treasure trove of rare and exquisitely detailed antiques

This bar named after the world's first mixed cocktail was home to one of New Orleans' most notorious politicians.

The South's nickname was supposedly born at a former bank in New Orleans' French Quarter.

This New Orleans statue of a portly figure in a goofy hat pays homage to a classic of satirical literature.

The neighborhood surrounding the memorial was the epicenter of the AIDS epidemic in Louisiana.

A pink cottage covered in hearts served as a haven and a resting place for LGBTQ activists.