The oldest standing structure in downtown San Diego.

The hidden jewel of Disneyland: a members only playground for the Disney elite.

From sax to spuds, get 'em all at this landmark music establishment.

Once strictly off-limits, this lower level housing curious and priceless vehicles of the Petersen Automotive Museum is now open to the public.

A California city claims to be the home of a fast-food classic.

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

A bigger-than-life pun that has become a beacon of altruism.

A couple turned their front yard into an artistic masterpiece.

Inside this library, the history of Los Angeles is retold through a mural.

Apartment building was once posh playground to the Hollywood elite.

"Prepare yourself! You are to become the voice of Interplanetary Parliament."

This quirky UFO-shaped curiosity is often mistaken for the airport’s control tower.

Entering this curiosity shop is like stepping into a mad scientist's lab.

This abandoned boat sits on a nude beach, is shaped like a UFO, and is covered in graffiti.

A quirky Poe-themed joint on an island keen to celebrate its overlooked connection to the famous writer.

This ''hidden'' 19th-century bridge played a simple, yet important role during the Spanish-American War.

This 20th-century mansion plays a key role in one of Puerto Rico's greatest novels.

This former railroad bridge was named after the great river that once flowed below it.

This small fort played a huge role defending Puerto Rico’s capital city.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

The location of Puerto Rico's first water bottling plant, thanks to a collaboration between Mother Nature and technology.

This chapel on a cliff is renowned for its healing powers and was founded on the site of a supposed divine intervention.

Rusting, graffiti-covered tanks litter the beach of this island, once used by the U.S. military for target practice.

Each August, one of the largest religious (and food) celebrations in the country is held in Boston.