This set of photos has to be seen to be believed. A party of explorers decided they wanted to see the world’s largest lava lake (containing an estimated 282 million cubic feet of lava! That’s all!). This involved going to Congo, climbing a mountain, abseiling down into a crater with 1,300lb of equipment, camping amid volcanic gases… Etc. Anyway. You really need to see the pictures. Thanks Pete for the suggestion! These are my favourites:

Marc Caillet with 282 million cubic feet of lava