I will be visiting Mammoth Cave with a friend in a few weeks. We are both 20 years old and enjoy nature, wildlife, and scenery. We will be there for just one day, a Sunday, and we want to see what there is to see and move on. How much time should I plan on spending there? Is 2 hours sharp enough or do I need to leave room for more sightseeing? I really want to see and enjoy the place, and not in a crazy rushed way-so how much time do I need?