I had an idea for a jungle-based campaign that would use the old adventure I1, Dwellers of the Forbidden City, as the crux. There were also two interesting adventures set in the same jungle area in old back-issues of Dungeon magazine, "The Leopard Men" and "The Elephants' Graveyard" if I remember correctly. The author was interested in making more adventures in an African-style setting.
Now that I'm learning the Forgotten Realms I think it would be really cool to situate such a campaign in Chult. Robert Howard wrote some Conan stories that really capture the experience of being on a jungle frontier to me.