One of the secrets of Mammoth Cave National Park is that the surface environment is spectacular. The park is host to an extensive trail system and limited access roads. Two ferries are operated seasonally in the park to provide access to less-visited backcountry in the park. Fall and spring are perhaps the most idea times to visit the park. The summer can be hot, humid, and buggy, and snow and ice conditions may prevail during the winter months. However, the temperature in the caverns is a steady year-round average of about 52 degrees Fahrenheit.