Some believe Ponce de León's mystical spring lurks right under a public drinking fountain.

A series of magical limestone formations along the coastline of the country island of Antigua.

A visionary Italian architect created an impressive cluster of concrete structures for a family's private tomb.

Canyon walls shrouded in ferns.

These hilltop ruins of a forgotten Buddhist monastery flourished in Antiquity from trade with the Roman Empire.

A miniature beach in the middle of the desert.

Sip creative cocktails in the former vault of the Riggs Bank.

A tunnel that brings more than a century of history to life from the deepest parts of the Niagara Gorge.

One of the first amphibian migration tunnels in the United States encourages a tradition that has inspired Amherst residents for decades.

Let these towering termite-building structures tell you where to go.

This modern monument to pagan belief looks like it was transported straight from ancient times.

Check out a hidden collection of vintage neon signs.

The mass grave of a heroic Revolutionary War regiment sits below an empty lot near the Gowanus Canal.

Volunteer-run library dedicated to exploring five decades of activism history.

One of the remaining markers of an era when Brooklyn and Flatbush were separate cities.

A hidden architectural treasure in New York's Brooklyn.

From a canyon-like gorge, more than 20 million gallons of water emerge every day, while a smaller spring drips down, creating the illusion of an endless, gentle waterfall.

Dine on ceviche tacos in the sea at this floating restaurant only accessible by boat.

These hooded graves are the only of their kind in the United States.

Deep into the lower floors of Pike Place, find a date with fowl fate.

These unique "earth pyramid" clay columns can be found in ravines around the village of Tirolo.

Located in a remote part of a Louisiana wildlife refuge, this tree has been standing for more than 1,200 years.

Known as the most resilient water tower in the region.

Is this 47.7-mile stretch of highway the longest straight road in the United States?