An island in the middle of a lake, in the middle of a volcano, in the middle of a bigger lake, in the middle of a bigger island, in an archipelago, in the Pacific Ocean.

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

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

Mount Nyiragongo has erupted at least 34 times since 1882 and is home to the world's largest lava lake.

Fire meets ice at the southernmost volcano on Earth.

This gracefully curving formation looks like a massive wave that was suddenly turned to stone.

This extraordinary geological oddity resembles human-made pavement.

The only pollutant in the clear blue water is sunscreen.

A massive concentration of algae is responsible for this lake's pink hue.

Microscopic fossils suggest Australia may be the birthplace of sulphur-based life forms.

Aqua white sand highlighted with fiery red rocks.

This pair of Australian "waterfalls" appear to be falling straight across the land.

Nine limestone rock stacks on Australia's "Shipwreck Coast."

A clear example of the process of erosion in action.

Clusters of huge boulders in the Australian Outback.

The tallest sea cliffs on the Southern Hemisphere are a climber's worst nightmare.

This trio of Australian rock spires may have inspired aboriginal legend or just modern tourism.

The unique ecosystem atop an Australian mountain is home to some colorful inhabitants.

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.

Australian Lake set aglow by Noctiluca Scintillans.

This dramatic sea spire is home to the world's rarest insect and is part of the lost continent of Zealandia.

An Australian lake whose pink hue defies scientific explanation.

A thin pane of glass keeps visitors from sliding off this futuristic skywalk.