This wet cave, now a part of the Barton Creek Archeological Reserve in a remote area off the Mountain Pine Ridge Road, offers a canoeing adventure in Xibalba (the Mayan underworld.) You'll float through about a mile of a long underground chamber—the cave is nearly 5 miles (8 km) long and parts have never been completely explored. You'll see Mayan ceramics along with ancient calcified skeletal remains and skulls. You can go on a tour from San Ignacio or from your lodge. PACZ Tours, for example, offers a six-hour tour, including lunch and admission to the cave, for BZ$170 plus tax per person, and Chaa Creek offers a half-day tour for one to four persons for BZ$310 plus BZ$50 per person for park admission and equipment plus tax. You can also drive to the cave yourself, rent a boat and gear, and hire a guide near the cave. Getting to the cave is an adventure in itself, requiring a long drive on rough roads. Parts of the road and the cave itself may be inaccessible after hard rains. Be careful in the cave; it's best to tour with a reputable tour company with an experienced tour guide and reliable, well-maintained equipment such as float vests.