Yesterday, we made our way to Rio Pasión, a major tributary of Rio Usumacinta. Although I personally favor Rio Grijalva as the River Sidon, Usumacinta is also a leading candidate. We took a boat along the Pasión for about 2 hours, and the scenery was gorgeous! We were far from civilization, in the midst of the jungle by the time we got off the boat. From there, we hiked into the depths of the jungle until we came to Ceibal.