One of the tourist attractions on the outskirts of Ponta Delgada is the Gruta do Carvao, which is an old lava tube. I found it quite interesting and a complete contrast to the many water made cave systems I’ve visited. This photo has been ‘recovered’ using some extensive photoshop manipulation – at the very moment I wanted to use the pop-up flash on my Canon 80D it decided it didn’t want to work. I tried in vain to find some obscure control in the menu system but with no luck. When we returned home I had to send my camera off to Canon for repair…. and of course it was out of warranty!
—Stephen—
Stephen G Hipperson 
No worries (though of course the Canon being out of warranty was so) because the image looks suitably Hadean, as I’m sure it was intended to be!
Thanks!