A marvel of Byzantine engineering under the streets of Istanbul.

Legend says if you stick your thumb in the hole and it gets wet your wish will be granted.

This historic hotel preserves many treasures from its heyday hosting passengers on the Orient Express.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

When ecosystems collide in the arid Southwest.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

Belly up to the bar in Cowtown, don't forget to buy some boots.

A "Texanic" (gigantic Texas) collection of Art Deco architecture at Dallas' historic Fair Park.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

A collection of fading fantasy tchotchkes lines this dirt road in the Colorado wilderness.

Even in death, he's still your huckleberry.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

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

There are eight natural springs around town, each with a slightly different taste.

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

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

This super steep hike ascends 2,000 feet in less than a mile.

One of the Eight Wonders of Kansas and the first official National Natural Monument these stark formations look like nature's Stonehenge.

An adorably sweet display of sculpted Precious Moments figurines.

A museum documents the development of the invention that tamed the Wild West.

This 41,000-acre wetland complex is the largest marsh in the interior of the United States.

Two hundred tons of pioneer artifacts were painstakingly recovered from a shipwreck at the bottom of the Missouri River.

Four, 18-foot-tall badminton shuttlecocks lie scattered about the lawn of a Kansas City museum.