[Primitive Technology: Reusable charcoal mound] (Viewer #3,923,164)

I’m still not sure what use charcoal is in the jungle, but the description assures me “Charcoal is a valuable fuel that reaches a higher temperature than the very wood it’s made from,” so I’ll just take his word for it that it’s worth all this fuss and bother.

By the way, I recommend either hitting the CC button to turn on subtitles, or reading the description under the video at the link, because it’s otherwise not always obvious what he’s doing or why.