A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

The narrowest street in Paris.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

France's most famous cemetery, with some of its most curious tombs.

Pilgrimage site for star-crossed lovers.

The world's most active stratovolcano is almost always erupting.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

Once the site of the Hawaiian monarchy, this building was originally designed as a palace.

This historic hotel invented the chocolate brownie.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

A rather vulgar example of the transition from Latin to the Italian vernacular.

A Nesting Doll of Churches.

Legend has it that this bronze orb, which sat atop an ancient Egyptian obelisk, once held the ashes of Julius Caesar.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

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

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

Architectureal fantasy quarter of Rome.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

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