The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

Eighty million natural history specimens call this gargantuan museum home.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This limestone cave offers an incredible view of the Río Grande de Arecibo valley.

Rusting, graffiti-covered tanks litter the beach of this island, once used by the U.S. military for target practice.

The world's brightest bioluminescent bay.

The meteor that sealed the fate of the dinosaurs landed at this site, one of the largest impact craters in the world.

One of the few places where you can visit a cenote and Maya ruins at the same time.

Three sinkholes filled with warm, crystal-clear water reached by a horse-driven cart on an old train track through the jungle.

Every equinox this Maya pyramid puts on a spooky ancient light show.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

Found down a long dirt road, a sacred Mexican cenote and 18th-century hacienda remain hidden.

These azure waters were thought to lead to the Mayan Underworld.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

This popular cave pool is truly magical, despite the crowds.

Take a dip beneath the stalactites in this amazing cenote.

Underwater art project will double as a massive artificial coral reef to help regenerate the damaged ecosystem.

An ancient system of freshwater caves filled with animal bones, including that of species long-extinct.

Cave where bat-eating snakes hang down from the ceiling.

At least seven hues of blue and turquoise make this freshwater lagoon unique.

A hidden treasure of an abandoned city lies deep in the jungles of Campeche, Mexico.