Cayo has quite a few entrances to Xibalba. Read about 7 of the more common caves in Cayo in this travel article from Chaa Creek. Did you know that the sink hole near St. Herman's Cave is called Actun Loch Tunich?
"Caves tell the history of Belize, having been an intricate part of the Maya religion and culture. The Maya used caves as ceremonial sites and evidence of these activities can be found inside these caves. Relics, principally in the form of shards of pottery, are very common."