The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

An Inca spa, military outpost or maybe… both?

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

View the California coastline (and the home of Barbara Streisand) inch by inch with stunning, government-sanctioned aerial photography.

The ruins of the movie ranch owned by actor and stuntman Ray "Crash" Corrigan.

This inanimate goat created by the "welding nun" has been helping to clean up the city of Spokane for more than 40 years.

The quiet canyon has a tumultuous history involving a doomsday cult.

Protected from the elements, these Native American rock paintings have survived approximately 250 years.

This statue of the great Argentinian car driver is located near a famous curve of the Monaco Grand Prix.

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

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

The underground sanctuary of a mysterious ancient cult.

An enigmatic modern marker left next to a historic Roman site.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

Remnants of a 4th-century church with vivid medieval frescoes and ancient sarcophagi hide beneath this old basilica.

One of the largest caves in the world open to the public.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

In the past, Renaissance sex workers were encouraged to entice customers on this bridge.

This deconsecrated church has seen many uses, from a tobacco storehouse to a cinema.

100 year tradition of fist fights, marked by marble footsteps.

Where Venice's gondolas go for a tune-up.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

The pile of books behind the dignified writer gave the statue a most undignified nickname.