Cauldron

Taken from a helicopter at the Holuhraun eruption site.
It's settled right down now, and what was previously molten rock thrown several hundred metres into the air from a crater measuring roughly 500x100 metres and around 80m high, has now reduced to something much less violent, and is confined to what looks like a witches' cauldron at one end of that initial massive crater. It's created a lava field of around 90 square km.

That cauldron is still around 40m across, though... and it still blows your mind seeing it up close. There is something about the concept of heat sufficient to melt rock that the human brain can't quite grasp. Well, mine can't. Like a chameleon put on a colour it can't quite manage... I noted this even when standing on lava around 150 years old, that still looks quite fresh and cannot be anything other than molten rock.
Seeing it actually melt, and bubble, and so forth, is another level of can't quite grasp altogether!

Oh... and when I say 'close', what I mean is flying directly above it and around it, close enough to feel the heat.
Neither this, nor any of my other 500 odd photos give even the smallest idea of what that's like. Put this on your bucket list, is my advice.