The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

Elvis's own personal tropical hideaway.

More than 2,000 species of tropical plants call this nature preserve and sanctuary home.

These ancient sacred grounds granted amnesty to those who managed to reach them.

Canada's subterranean Cold War museum has doubled as a movie set.

An underground city of salt.

A tunnel with windows, so you don't miss out on the impressive views.

After sunset the heart of Zanzibar's historic Stone Town neighborhood transforms into a culinary playground.

One of the highest mountain passes in Europe has been ranked among the best driving roads in the world.

A once-thriving hotel in the Swiss Alps couldn't compete with climate change.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

This massive mall has hundreds of shops, an amusement park, and a history of deadly amusement attractions.

This historic black and white monastery is one of Bulgaria's architectural jewels.

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

The prototype for all Nazi concentration camps.

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

An emerald-green grotto just a short trip from Austin.