The abstract sandstone rock formations at this Algerian national park are rich with prehistoric art.

The world is full of swimming holes, but few compare to Samoa’s idyllic To Sua ocean trench.

A newspaper editor turned this abandoned island into a tortoise nature preserve that's now the world's smallest national park.

Dramatic river bend surrounds a natural red-rocked pedestal.

A shrine contains nearly 200 statues of the Buddhist deity Jizo, dressed in bibs by parents who have lost a child.

The red crab exhibits one of the most spectacular migrations on earth, despite manmade obstacles.

This "preacher's pulpit" once used for pagan ritual, is home to a new, and dangerous ritual.

Structure built from the skulls of vanquished foes.

This spectacular bridge supported by two gigantic hands looks like something out of a fantasy universe.

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.

A church of bones, decorated with 40,000 human skeletons.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

Tubing through a cave lit with glowworms is a magical underground experience.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

This African beach is home to thousands of rare mainland penguins that are known for their annoying voice.

Hot springs monkey spa in the middle of Hell's Valley.

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.

Fire meets ice at the southernmost volcano on Earth.

Dozens of snakes are housed and worshipped within the walls of this Vodun temple.