Horace Carver Hovey's A Practical Guide to Adjustable Routes in Kentucky's Mammoth Cave is an important source of information for those interested in the world's largest cave. This book contains detailed information about the practical aspects of excursions in Mammoth Cave, including a description of regulated routes, tips and recommendations for preparing for the hike. The author provides comprehensive guidelines for safety when visiting the cave, making the book an indispensable guide for tourists and explorers. Thanks to this book, the reader will be able to better understand the uniqueness of the Mammoth Cave and enjoy its majesty during a virtual or real trip.