A toxic ghost town sitting atop a massive coal fire.

Infamous marsh filled with toxic waste, World War II-era London rubble, and dead mobsters galore.

This "dead marsh" sits among the largest sand dunes in the world, a forest frozen in time.

A seemingly endless landscape of pure salt stretches far across Bolivia.

A lake with hundreds of ancient skeletons surrounding it. The surprise is what killed them.

Home to nearly a third of the world's mud volcanoes, Azerbaijan is home to a messy, bubbling, and sometimes explosive landscape.

Think you have a tough job? Try carrying 200 kilos through a cloud of sulfur down the side of a volcano.

This "floating island" plateau sits 7,671 feet above the forest floor.

The rocks in this arid basin leave trails of movement behind them.

The world's first and only natural nuclear reactor.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.