Nakum, Naranjo and Yaxhá are part of the same natural reserve/protected area. About how much of it is beefed up, the places are in fact important archaeological sites with pyramids and estelas of diferent size. The whole area is filled with wildlife. The Lake (Yaxhá) has crocodriles... The wildlife around these sites is pretty diverse, finding birds, saraguates, jaguares and reptiles of many many kinds. Yaxhá is about 24km from Tikal in straight line (60km by car) and the other places (Nakum and Naranjo) are about 12km by trails from Yaxhá. I'm updating this post as many people seem to be ending up with this page looking for info about the area. So, by now (march 2008) Yaxhá is the only site easily reachable by car, Nakum and Naranjo still need time and effort walking on selvatic trails, try to avoid the winter as it gets messy... about "coming across with something like that" yes, I have seen the crocs, some gigantic yellowish iguanas, saraguates, some other monkeys http://www.ciudadesmayas.com