This cave is about 250-300 million years old and was covered by the sea. Coronado cave was formed by water Calcite grains in the Limestone and slowly dissolved by the water. You will notice the many flat limestone slabs on the trail as you hike up. Pyrite rocks surround the cave. The cave is 600 feet wide and 20 inches high and70 feet wide with a lot of space to crawl through if you wish! Also, I did not find any creepy crawlers when I explored it, I was happy about it! So, it’s free, and you can go at your own pace, like I said You got to explore the Coronado cave!