Collapse into a round lava lake after it drained. The source of the lava is the lavafall in the background.
<a href="//commons.wikimedia.org/wiki/User:Dave_Bunnell" title="User:Dave Bunnell">Dave Bunnell / Under Earth Images</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>