An Australian lake whose pink hue defies scientific explanation.

The world’s most primitive form of bungee jumping.

Clusters of huge boulders in the Australian Outback.

White cockroaches and other cave species occupy this massive series of lava tubes.

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.

The only pollutant in the clear blue water is sunscreen.

Prehistoric park filled with the fossils of dozens of extinct species including Australian megafauna.

Australian Lake set aglow by Noctiluca Scintillans.

Started nearly 100 years ago, this science experiment just keeps on going, ever so slowly.

6000-year-old coal fire moves one meter per year.

By standing on a particular paving stone in the courtyard, you'll hear an echo that shouldn't be.

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

Gigantic unfinished stupa and the world's 2nd largest bell.

An ancient jungle temple carved into a rocky overhang of the Dane Soung Plateau.

The most disputed archipelago in the world.

World's largest cave was only discovered in 1991, and now offers tours to the public.

A quick and simple solution to Cambodia's train woes.

A former French military respite turned jungle tourism hotspot.