Pittsburgh's literal underground railroad.

Hundreds of protractors affixed to surfaces all over the city.

This icon of the Atomic Age now lays dormant.

A model of a dinosaur that was named for Andrew Carnegie stands outside the museum that also bears his name.

This water-powered cliffside railway is one of the steepest funiculars in the world.

There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

This innovative steam machine was no doubt the most famous of the pioneer locomotives.

This bomb shelter-themed bar has barely changed since it opened.

The remains of this rugged homestead ranch offer a brief glimpse into a bygone era.

Miniature art that tells an enormous story.

An early 20th-century jail not far from the infamous Tombstone, Arizona.

A high point in Vancouver kitsch.

A Wild West jailhouse that slid down the mountainside.

A strenuous, unofficial trail leads to spectacular views in one of America's most remote national monuments.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

One of the world's largest telescopes, stares into the night sky with two huge mirrors.

A miniature Italianate fantasy village on the coast of Wales and the set of ITC classic "The Prisoner."

A century after his death, this covered bridge still calls to mind the plein air painter who loved it.

One of the largest crucifixes in the world stands 55 feet tall in a secluded, wooded area of northern Michigan.

A real-life Professor Snape once taught in this Welsh university building, which students of course nicknamed “Hogwarts.”

After years of slow decline, a derelict Gothic castle is now being restored to life.

This 19th-century ghost town offers a stunning view of Lake Michigan and a journey through the region's industrial past.

One of few surviving standpipe water towers in the U.S.

A floating museum that was sunk by a flood and left to rot in the tides.