The Howler Monkey is easily found in the southern part of Quintana Roo and Campeche near the Calakmul and Kohunlich ruins. We recently retraced some of our past adventures and came across the Howler Monkeys yet again. This video is what the monkeys really sound like. It was freaky, intriguing, and amazing all at the same time! Video of the Howler Monkey Find out more about the Calakmul Ruins and Kohunlich Ruins in the southern part of the state.