When a cracker would fall into the muck, Alex's father would stomp on it before the oblivious little boy could scoop it up and put it into his mouth. The water rushes in to the cave and, as it recedes, comes rushing out with a boom that sometimes sounds like thunder. When Alex was there, Thunder Hole was relatively tame, but it was making enough noise to make him uneasy. He preferred to look at Thunder Hole from a distance. The visit did make an impression on him.
Nobody knows for sure.
After Acadia National Park, Alexander's New England odyssey would continue, in Plymouth, Massachusetts . The Alexander Home Page , a division of LeapToad Enterprises .