Urup Island

This unusual lava tube spouts seawater during high surf.

A steaming, boiling hellscape sources Hokkaido's thermal baths.

A turquoise lake within a volcanic crater.

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

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

The once and future home of New Zealand's famed Pink and White Terraces.

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.