A wonder of natural limestone formations etched by millions of years of natural interaction between rainfall and rock and air.

A beautiful, but toxic, lake formed by mining.

Rainforest filled with record-holding eucalyptus.

One of Australia's largest secondhand bookstores.

Built over an abandoned train yard, this hidden gem is full of winding paths and offers gorgeous views of Sydney Harbour.

A massive stairway that almost wasn't leads to one of Australia's most scenic vistas.

Once the path of a railway tunnel, now home to thousands of glowing insects.

Nature is leading a successful mutiny on this century-old freighter.

A collection of outdoor mystical statues paying homage to indigenous Australians and ecological stewardship.

A castle hand-built by a Spanish dreamer in the Australian tropical jungle.

An abandoned railroad tunnel is now filled with bioluminescent bugs.

A taste of Egypt on the outskirts of Geelong.

Inside a busy metro station, an impressive mural depicts the prehispanic city of Tenochtitlán.

The ruins of the bathhouse used by the ill-fated last Aztec emperor still lie in Chapultepec Park.

The striking jade death mask of an ancient Maya king is displayed in a replica tomb in Mexico City.

The Mexican painter Diego Rivera created this unusual museum to display his collection of pre-Hispanic artifacts.

This colossal ancient sculpture of the monstrous Aztec rain god has a literally stormy history.

Psychedelic murals coat the inside of a nondescript research library.

This incredible college library is a visual masterpiece of mosaic art. It also looks kind of like a giant boombox.

CDMX's home for the world's culinary delights.

This old-school café is famous for serving coffee, chilaquiles, and the Cuban Revolution.

Mexico City's largest market contains a Willy Wonka-esque wonderland.

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

A museum in the former home of Marxist revolutionary Leon Trotsky.