Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

This museum started as a collection of Manhattan Projects and continues to add exhibits as they are declassified.

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

One part antique store, one part curiosities hodge-podge.

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 1,215-foot tunnel transports pedestrians beneath the River Thames.

A cluttered and astounding collection of antiquities and curiosities.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

The magic's in the hole!

This expansive bridge in the Canadian wilderness was originally just built for friends.

Medicinal spa created with the discharge from a geothermal energy plant.

Giant acorn-shaped 19th century gazebo from which suburban Washingtonians gazed upon the original "silver" spring.

At 207 feet, one of the world's longest continuous escalators.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

A haunting tribute to pioneering photographer Clover Adams.

Largest Roman Catholic church in North America.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

While most of the games in this arcade take quarters, that would have been a small fortune when they were made.

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

The largest self-built castle in the U.S., six decades in the making.