15+ years ago the Darien really was more dangerous due to guerilla activity that, while still present, has abated. You might want to read Karl Bushby’s account

15+ years ago the Darien really was more dangerous due to guerilla activity that, while still present, has abated. You might want to read Karl Bushby’s account of walking the Darien Gap around the turn of the millennium, and listen to interviews he has given on the subject. He had to coordinate his traversal with the Colombian military and, as a former soldier himself interested in intelligence matters, he got a good idea of just how much was going on in the jungle at that time. Not only the anti-government FARC but also right-wing militias that could be just as dicey.