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

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

The biggest solar telescope in the world helps reveal the secrets of our sun.

After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

America's only nuclear missile silo open to the public.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

San Francisco's newly reopened hands-on science museum.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

The Goose Girl of Göttingen, Germany might well be the most kissed girl in the world.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

Pompeii's less famous neighbor is still revealing her secrets.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Descend 2,030 years into the past in an ancient tunnel built to support Jerusalem's most famous wall.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.