Marking the spot where a conquistador gave up his search for the fabled Seven Cities of Gold.

A six-story-tall golden pyramid, surrounded by a moat.

A New England curiosity cabinet, one hundred years on.

What was once the second largest steel mill in the US is now a sprawling complex of modern ruins.

Developers built a Walmart around one family's plot and constructed a mausoleum in the parking lot.

Amazing pre-Civil War ruins alongside a shallow, rocky river that hosts beautiful (but endangered) lilies.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

A deteriorating 1990s Girl Scout camp in a beautiful lush park on Lake Ontario.

One man's real life disfigurement inspired a lasting local legend surrounding an eerie tunnel.

A "haunted" landmark on the coast of Southern California.

Pennsylvania's own Roswell-style UFO mystery.

A metal ring in the middle of the road marks the exact spot where the Soviet satellite crash-landed in 1962.

There’s a hidden military meme engraved on the World War II Memorial.

Mine your own precious stones.

Abandoned Air Force base that has fallen into disrepair.

This lovely university observatory continues to sit abandoned since its potential savior was sent to jail for fraud.

A hyper-luxurious, 12,000- square foot home might be buried beneath Queens, still waiting to protect you from nuclear missiles.

A miraculous natural phenomenon known as "the spring that breathes."

Neoclassical Revival mansion and set of horror cult classic Phantasm.

A Manhattan Episcopal church with an eerie underground crypt.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

The home of one of America's most wealthy industrialists is now a historic site that remembers a more decadent time in the country's history.

Strange physical sensations and optical contradictions keep visitors coming back for more.

An old trolley bridge was converted into a breathtaking garden bursting with colorful flowers.