This massive underground salt mine now holds a sci-fi theme park in its depths.

The 43-mile route crosses through six islands with gorgeous views of the Seto Inland Sea.

These Great Lakes sea caves accessible by boat in the summer turn into temples of ice reachable by foot in the winter.

This historic, palatial theater is now one of the world’s most beautiful bookstores.

The first and only carousel with a lineup entirely of insects.

This lab's maddening silence is good for business but bad for sanity.

A fiery crater has been burning in the Karakum Desert since 1971.

Locals transformed this Canadian evergreen into a secret hangout with spectacular views of Vancouver's skyline.

This odd Chilean waterfall-cano hotel must be entered via a rope bridge.

One of the world's few mounted blue whales, its jaws are hinged open allowing visitors to descend into a lounge.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

An eatery in a shallow river where diners can enjoy their meal mere feet from the base of an artificial waterfall.

Read a book next to a Midtown waterfall.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

A small peaceful park and waterfall tucked amid the urban grind of Midtown Manhattan.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

A remote candy-striped mountain in the Peruvian Andes straight out of the pages of Dr. Seuss.

A Hawaiian stairway to heaven—that you can't climb.

A part of the world's largest marsh seems to be growing bright red Martian grass.

An enormous, inside-out glass globe built in 1935.

Dim sum, served in a grand old theater.

A South African bar inside a hollowed out 6,000-year-old Baobab.

Sleep in a glass pod dangling off a cliff.

An ancient stone fortress considered by many to be the eighth wonder of the world.