The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A herd of 150 bison live on California's Santa Catalina Island and are at the heart of an ongoing debate between environmental protection and economic expansion.

An alley covered with 20 years of bubble gum.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

A museum dedicated to exhibiting remarkable outsider art.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

340 bicycles, 65 feet high.

This whimsical seashell-shaped place of worship was designed to blend into its surroundings.

This Peruvian canyon is filled with geometric salt pools that have been being harvested since the Incan empire.

These steeply terraced ruins are a stop along the Inca Trail to Machu Picchu.

If you’ve ever seen a picture of Machu Picchu, then you’ve seen a picture of Huayna Picchu—you just didn’t realize it.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

The first green space constructed on an elevated viaduct.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

Steinbeck's old stomping grounds, immortalized in Cannery Row.

More than 700 species live within this murky marvel of a swamp on California's coast.

Once America’s most beautiful army base, this abandoned military fort on the coast of Monterey Bay has been left to the elements.

Historic funicular railway, believed to be the shortest railroad in the world.

A beautiful memorial tells the story of a formerly enslaved woman whose kindness shaped a burgeoning city.

A living time capsule of the 1960s Richardson Bay water-front.

The mysterious round rocks of Schooner Gulch.

Smooth basaltic rocks tell a tale of ancient glacial waterfalls.

An Aladdin's cave of old Silicon Valley tech.

A giant can of fruit cocktail is all that remains of what was once the world's largest cannery.