Rome's ancient Etruscan rival, now a park full of ruins.

A modern sliver of architecture in Roma.

This large, circular tomb is the final resting place of the first emperor of Rome.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

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

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

A Nesting Doll of Churches.

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

Jesus' footprints and the first catacombs in the world.

2300-year-old Roman road connecting the empire.

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."

An impressive collection of over 50,000 minerals including moon rock from the Apollo 17 mission.

This iconic science fiction house still looks like something from the future.

Travel through the wholesome amusements of yesteryear at this charming miniature village.

The final resting place of American icon Buffalo Bill, and a museum that aids in telling his tale.

A small horde of mythical creatures lurk almost imperceptibly within the museum's wildlife dioramas.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

This super steep hike ascends 2,000 feet in less than a mile.