Journey into the heart of the Mayan underworld at the Actun Tunichil Muknal (ATM) cave. Departing from San Ignacio, this guided, action-packed 9-hour tour kicks off with a 45-minute, physically intense jungle hike through the Tapir Nature Reserve to the entrance of the cave. Swim, climb, and spelunk your way through astonishing caverns into the depths of the cave, where you’ll get an up-close look at artifacts and offerings used in ancient Mayan ceremonies. Round-trip transport and riverside lunch are included. Please note this tour isn't recommended for those with a fear of enclosed spaces or heights.