Inner Space Cavern, Georgetown

###By the Numbers: Inner Space Cavern * **1963**—the year the cavern was discovered by a state highway drilling team * **7,000** square feet surveyed after the cavern was discovered * **44** species of animal fossils found in the cave * **72** degrees Fahrenheit—the temperature inside the cavern * **100 million**—the estimated age of the oldest rock in the cavern * **14** sites on a basic tour, such as Soda Straw Balcony and Bone Sink * **1.25** hours—the length of a beginner tour * **1.5** hours—the length of an intermediate tour * **4** hours—the length of an advanced tour