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

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

Known as the Hintz House, this medieval pharmacy has been an apothecary's haven for nearly 450 years.

This snug medieval lane is one of the narrowest streets in the world.

A giant portrait of an ancient king looms over the river.

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

This once-derelict building is now one of the most beautiful bookstores in the world.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

This massive underground salt mine now holds a sci-fi theme park in its depths.

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

A creek tumbles over a series of step-like rocks to create this scenic water feature.

See just what life was like in a 19th-century prospecting town.

Home to the deepest rift anywhere on Earth.

Most-visited and most-photographed slot canyon in the American Southwest.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

Giant pinnacles in the sun-scorched lands of Southern Utah have been nicknamed "white ghosts."

Largest collection of mounted dinosaur specimens in the world.

Drive up a paved road into "Nevada's Yosemite" for exquisite views and mountain hiking in an alpine setting.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

An attractive alpine lake at 8,400 feet that is accessible via a paved road.

A spectacular overlook of the Little Grand Canyon of the San Rafael River, a deep sandstone gorge streaked with orange, red and white in a remote, uncrowded part of Utah.

These tall, red sandstone pinnacles outside Moab are often forgotten amid their more famous neighbors.