Stretching across western Newfoundland lies an 1,100-mile expanse of the Appalachian Mountains, a picture-perfect corner of the Canadian wilderness: Gros Morne National Park. Embark on a sensory adventure through a land of glacier-carved fjords, cascading waterfalls, and soaring cliffs.

The Yucatan is a paradox: a rainforest where rainfall is rare, with no major rivers or streams. Instead, beneath the forest floor lies a mysterious ecosystem, an elaborate web of flooded caves known as 'cenotes'--Mayan for 'sacred wells'. More people have walked on the moon than have reached the end of these caverns, but their presence has fueled an astonishing diversity of life: from trees with hundred foot roots that still draw water, to a rich tapestry of exotic animals--like the howler monkeys whose cries fill the lush undergrowth.

The tectonic forces that bring life to Canada's rain-forest paradise, Vancouver Island, belie a dangerous feature: the inevitability of a megathrust earthquake that could trigger a 4,000-mile tsunami! The question scientists have yet to answer is when it will strike.

Ireland is a land studded with majestic natural landmarks. Learn the history and myths behind the distinctive features of this rugged island, including the 700-foot-tall Cliffs of Moher, the 40,000 stone columns known as Giant's Causeway, and Slieve Gullion, a mountain that rose from molten rock.

Mosses that tower 10 stories high and insects of horror-film proportions are part of the Bay of Fundy's peculiar ecosystem, which dates back hundreds of millions of years. With the highest tides on Earth, waves rip rocks off cliffs and reveal fossils that are vital to understanding the history of our planet.

Lake Superior is a rugged natural wonder and an ancient haven for remarkable geological and cultural history. Step into the picturesque settings of one of North America's most important natural regions and learn about the unique history of its indigenous people.

The hostile waters surrounding Wales have caused hundreds of shipwrecks and sculpted the stunning scenery of its wild coastline. Take a serene tour of the world's longest continuous coastal footpath and explore its mysterious caves, cliffs full of fossils, and causeways that disappear.

The Sierra Gorda isn't one world, but a patchwork of distinct landscapes separated only by mountainous elevation. From mist-covered cloud forests on the east side to a rain-deprived desert on the west, the Sierra Gorda is comprised of towering cacti, a crystalline river inhabited by the unique axolotl, and a 1,400-foot monolith that stands as a tribute to the region's volcanic past. Higher up, tropical and alpine species of fauna and flora intermingle, creating the signature diversity unique to the "wild heart of central Mexico."

Perched between the Pacific Ocean and the Caribbean Sea lies Costa Rica: a tropical corridor brought to life by moisture-laden trade winds, raging rivers, and active volcanoes that simmer ominously. Together, they make up a fertile paradise of cloud forests that are home to green iguanas, sloths, and aptly named howler monkeys. The startling diversity extends to the surrounding coastal waters, where the mangrove forests provide an unlikely nursery to one of the ocean's most exotic predators: the hammerhead shark.

Stretching along 600 miles of Northern Chile's Pacific coast is the dryest non-polar region on Earth: the desolate Atacama Desert. From menacing volcanoes to wondrous natural geysers, experience one of South America's last great wild lands, one that few have ever laid eyes on.