Laguna Petexbatún is a shallow, turbid 6km-long lake southwest of Sayaxché, approached by an hour's lancha ride up the Río Petexbatún, a tributary of the Río de la Pasión. The lake, river and surrounding forests harbor many birds, including kingfishers, egrets, vultures, eagles, cormorants and herons. Though rare, the occasional crocodile sighting happens according to boat operators. It's a lovely spot made more lovely by its remoteness and the Amazon-like boat ride to get here from Sayaxché.
Within reach of the waterways are five significant archaeological sites and a pair of jungle-hideaway accommodations. The island of Chiminos (once a peninsula) was also significant in Maya times and now houses a beautiful ecolodge.