Once the most densely populated place in the world, this island is now a ghost town.

A road runs through the middle of this small Austrian chapel.

Finland's oldest astronomical observatory once played a crucial role in seafaring and timekeeping.

An otherworldly restaurant perched on the edge of a jagged cliff next to a medieval holy city.

This comprehensive collection features Native American artifacts dating back centuries.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A mountaintop space observatory that is certified dark.

Caves famous for the dragon-slaying saint who lived there.

Finale of "William Tell Overture" can be heard as drivers pass over grooves in the road.

Before founding the American Red Cross, Clara Barton had a tremendous humanitarian impact by locating thousands of missing soldiers.

This gallery of prehistoric red ochre art lines the wall of a scenic segment in Utah's San Rafael Swell.

A cemetery full of touching tombstones from a community of railroad workers, uranium miners, and Cold War missile launchers.

Contains a wealth of information about the first exploration and later use of the Green and Colorado Rivers.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

This colorfully-painted tunnel links two distinct parts of a historic neighborhood.

The world's first floating farm is staffed by one human, three robots, and 35 cows.

A statue of the second-tallest Dutchman in history.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

In the mountains of West Virginia is this perfectly preserved Art Deco train station.

The grand complex of buildings that comprise Liverpool's Exchange Flags includes a vast World War II bunker that has been frozen in time.

During the holidays, a vintage subway train whisks New Yorkers back in time.

This disused Cold War bunker has been restored to all of its early 60s glory.

A failed utopian experiment for British expats in the American South is now a Victorian village frozen in time.

Harry Potter’s Hogsmeade Station is also a charming blast from the past situated in North Yorkshire.