The longest continuous lava tube in Oregon.

The second largest waterfall by volume in the U.S., Willamette Falls is outdone only by Niagara in the amount of water that is pushed northward.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

This Oregon farm is dedicated to teaching people the professional art of tree climbing.

This French Canadian classic is a specialty of the oldest continually used church in Minneapolis.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Pagan monument converted to Christianity with the population.

A cluster of granite granaries perched on stilts.

An early Portuguese serial killer's head is alarmingly well preserved in a jar at the University of Lisbon.

The corpse bride of Portugal.

Local lore says the devil built this beautiful medieval bridge to help a fleeing bandit.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

This fairy-tale, neo-Gothic church in the Azores is a world of magical realism.

Dead weights honor the dead of Portugal's fishing industry.

At night, bats patrol this magnificent 18th-century space in search of book-eating pests.

Picturesque intersection of witchcraft and ancient Christianity.

A unique seaside cave where Aleister Crowley faked his own death.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

Houses are tucked between, on, and underneath giant boulders.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

These layered sandstone mountains in China look like they are made of pressed crayons.

This vertical pinnacle in China was the inspiration for the floating mountains in the movie “Avatar.”

A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.