A submerged archeological park still holds the wonders of a Roman Sodom.

Ancient ruins hidden underneath a modern luxury hotel.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

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

One of the now-less-hidden floral gems of the "Emerald Necklace."

One of the last remaining World War II Victory Gardens in the U.S. is quietly growing across from Fenway Park.

The massive machine creates cracking displays of indoor lightning.

The site of Paul Revere's historic two lantern warning.

The oldest Italian café in Boston, this spot also serves as a veritable museum of vintage coffee ephemera.

In the 19th century, this was the center of Boston's Black community.

This nearly 200-year-old restaurant's history includes an exiled French prince, JFK, and a very hungry Daniel Webster.

This “living museum” at UCLA exhibits thousands of plant species from all over the world.

Where the rich wintered in Pasadena.

This 1920s masterpiece of French Quarter architecture hides a secret tunnel used by Albert Einstein.

A nursery specializing in strange and beautiful succulents and cacti.

Explore an early California pioneer's rancho hidden in LA's manufacturing hinterland.

This general store offers visitors a glimpse back into the 1930s.

A meditative space out of a fantasy story.

A regular looking rock with an unbelievable history.

Experience a quartz crystal sound bath inside a storied, all-wood sound-chamber.

The most unique castle in all of Southern California, entirely constructed from repurposed materials.

A living museum dedicated to the legendary woodworker and his soulful furniture.

Hundreds of trees made from glass bottles make up this forest on Route 66.

The "Kill Bill Church" was transformed into a place of worship after a long Hollywood history.