You need a certified guide to enter the cave and you can’t go inside on your own. The cave periodically closes when rainfall causes the river’s water level to rise and flood parts of the cave. Unfortunately, cameras have been prohibited since 2012, when there were two accidents. Some tourists accidentally damaged some rare skeletal remains in the cave. One tourist actually dropped her camera onto a female Maya skull and damaged it. If you want to take some images inside of Actun Tunichil Muknal, you need permission from the Belizean National Institute of Culture and History (NICH).