Barton Creek Cave is a must-see thing to do in San Ignacio! This remote mountain cave is one of the largest river caves in Belize and is full of unique, intricate formations. The openness of the cave varies from huge cathedral ceilings to narrowly canoeing between draping formations. There is also evidence that Barton Creek Cave was used for Mayan ceremonial purposes. Artifacts include pottery shards and human remains that date back to about 1,800 years ago.