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

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

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

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

The underground sanctuary of a mysterious ancient cult.

The final resting place of the poets Shelley and Keats.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

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."

This legendary dessert was served to Nobel laureates for decades.

Hidden behind a wall, Spanish nuns distribute their signature sweets on a revolving tray.

The pharmacy's retro ice cream mixer is one of the last of its kind.

Though the original building has been demolished, these massive bronze doors were saved.

This hilltop park offers magnificent views and a Frank Lloyd Wright masterpiece.

A ghost town at the airport is now a refuge for blue butterflies.

This serene oasis in an affluent Los Angeles neighborhood holds some of Gandhi's ashes and got Elvis into Eastern Philosophy.

A spiritual retreat in the heart of Los Angeles offers stunning gardens and a labyrinth to lose yourself in.

The discovery of these rare, ancient artifacts led to the creation of a new museum.

This magnificent brick dome was made with an unusual design method.

This Gothic church houses ornate royal tombs and a magnificent gilded altarpiece.

This air raid shelter from the Spanish Civil War is now a museum dedicated to the history of the city's bombardment.

The magnificent sanctuary is Spain's first purpose-built structure of its kind.

Legends surround this natural rock formation that looks like a Moorish king wearing a crown.