The Kilauea Iki is a pit crater that erupted in 1959 that flowed for more than a month. Even 50 years later, it's still warm to the touch, but open to hike across.

Entering the crater, the vegetation returns when seeds fall into cracks, and dust and water enter.	The frequent rainfall seeps into the cracks and turns to water vapor, giving it the steaming look along the crater floor. Even after all this time, the surface is still warm, very warm in places.
This part of the edge of the crater collapsed during some of the lava flow.	More of the steam / water vapor that is rising skyward.	This gives a better sense of just how big the crater is; the rainbow is just a bonus, eh? (More rain...)