A lingering bit of Space Race nostalgia lies in the middle of the desert.

Abandoned city hidden from the world by tropical forest and isolation on the coast of Kenya.

Roman ruins top white travertine terraces formed by ancient hot springs.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

Legend has it that this stone moves down to the river sometimes to have a drink.

An architect transformed this abandoned cement factory into his castle-like workshop.

America's post-nuclear-attack chambers of Congress.

This harrowing climb along West Virginia's jagged spires is one of the only Via Ferrata on America's east coast.

Hikers can still stroll beneath the long conveyer of this abandoned mining facility hidden in a West Virginia river gorge.

Home of a 28-foot tall stalagmite known as the War Club.

Visit a replica of the estate where Aaron Burr allegedly plotted a treasonous scheme against the United States.

Take a steam-powered ride straight out of the past on this Appalachian rail line.

This lookout tower built in the 1930s is now an in-demand cabin with what might be the best view of the Seneca State Forest.

This former fire tower is now a rustic observatory that offers amazing views of eagles, hawks, and the Appalachian Mountains.

A beautiful hidden gem in central West Virginia.

This shale formation along the Appalachian Trail once inspired the third president of the United States.

The unique building practices of the Batammariba reflect the community's deep reverence for and connection to the earth.

What was once believed to be a church floor turned out to be the artwork of geology.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

One of the world's steepest streets seems to have houses sliding down it.

"Not too many people can say they've had a nuclear bomb dropped on them, not too many would want to." — Walter Gregg.

Incredible miniature towns and buildings created and decorated with thousands of tiny rocks.

The ruins of a 19th-century aqueduct run through this Brazilian island's deep forest.

The eccentric mansion of one the most popular horror authors of modern times.