The last street in Pittsburgh that's paved with wood.

Home of Howard Hughes' Spruce Goose.

This former Soviet military base has over 10 original aircraft and an enormous amount of memorabilia on display.

Approximately 300 million years ago, a massive coral reef existed in what is now the largest limestone cave in Japan.

One of the world’s largest cave systems houses legends, concerts, and wondrous rock formations alike.

This dreamy street will transport you to wintertime in Victorian England.

One of America’s oldest and spookiest hotels, thanks to the residency of ghosts, dead presidents, and Alfred Hitchcock.

This eight-mile stretch of road gets its name from a local legend about a lost soul searching for his head.

These otherworldly caverns form Earth's oldest known cave system.

A massive cave complex boasts some of the clearest water (and most charming bats) in the world.

Nearly 40 miles and 1,000 years of limestone mines under Denmark.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

An off-the-beaten path cave with an underground lake.

This remnant of an old railroad is the tallest surviving wooden trestle bridge in Victoria.

Train cars and railroad artifacts abound at this restaurant devoted to railway history.

Reaching this rock formation involves a hike through rocky rapids and springs where wild turtles reproduce.

These haunting ruins of a 700-year-old Prehispanic city have witnessed centuries of wars and massacres.

This partially reconstructed Aztec pyramid gives a glimpse of what its larger counterparts would have looked like.

A barbarous band of serpents guard the bases of these Aztec temples.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

The "dragon babies" of southeastern Europe.

A miniature train-ride through Slovenia's largest cave system.

This 600-year-old home seems to defy physics.