An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Go inside to really appreciate this 500-year-old technological masterpiece.

A medieval weapon rumored to have been used by the brilliant poet himself.

A slightly creepy gallery of plaster cast models in the same museum as Michelangelo's David.

Secret refuge and museum of the Duke of Florence.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

The middle finger of modernity.

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

A Nesting Doll of Churches.

2300-year-old Roman road connecting the empire.

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

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

This quirky hot springs town known to locals as "T or C" was named after a radio show.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

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

This blowhole is supposedly caused by a trapped monster.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

Giant telescope mirrors built in a spinning furnace under a college football stadium.