A monument celebrating the idea of reaching inaccessible places.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

A castle built by an eccentric medieval enthusiast in rural Ohio.

Take a drunken tour inside the world's largest known geode.

Deep scars on the earth left by the Ice Age.

A walk through the historic city center, under the streets of Seattle.

A man-made island in scenic San Francisco Bay.

An enormous illuminated figure dances on the Las Vegas strip.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

This massive redwood tree has a hole in the base big enough to drive through.

A pocket of jungle amidst urban expansion in Panama.