>>95989148 (OP)Populated by tribes of renegade demi-humans. They've mostly gone out there to flee from human populations. This has been happening long enough that the tribes vary between classic primitives to something more akin to modern day guerillas.
Because of necromancy, the lack of exorcists, and the sheer impenetrability of the jungle, much of it is also very, very haunted. Many cultural relics of the various jungle tribes are just detritus from the spirit world believed to be more important than they really are. The mass of the jungle is slowly being spiritually poisoned like this, but so is everywhere else.
The main people who go out in the jungle are adventurers, explorers, and criminals. Adventurers are typically out there to loot various tribal artifacts, though some church-sanctioned types focus more on exorcisms. Explorers are trying to find new resources and set up trade deals with any tribes that have something to offer worthy of the trip out there. Criminals go out there to escape the law, and to press-gang tribals as militias and slaves.