In about 1959, I went to Mammoth Cave with my family, I was 12 and fascinated by caves. Not long afterward, my short interest span made me forget about them. In 1997, my wife wanted me to go with her to see her mother in Virginia. I had been thinking of going back to Mammoth, so I said I'd go to Virginia, but wanted to stop at Mammoth Cave on the way. Janet called the Park Service to get an idea of what trips were offered. They have several 'tourist' trips, lights, paved pathways, etc., but during the conversation, the Service mentioned they had a 'Wild Cave' tour. Knowing me, Janet said that sounded like what we were interested in, so she booked the trip. The requirements were that you had to be 15 years old, not mind getting dirty, and have some boots with ankle support and light-colored soles (so not to mark the formations). They provided the helmets and lights. The Park Service bills this as the most strenuous ranger led activity in the National Park System. It was about five miles underground in about six hours. We ate like starved dogs at dinner after the trip. It was strenuous, but tons of fun. We really got the caving bug after Mammoth.