The book by the famous speleologist Alexander Efremov recreates in a fascinating literary form the history of the discovery of the “Great Caves,” found and explored on the territory of the former Soviet Union in the 60-80s of the last century. The truthful narrative closely intertwines stories about amazing adventures, about strong and fearless people, about funny, strange and dramatic events in the mountains and deep underground.

The book is intended for a wide range of readers, but primarily for young people eager to test themselves, find true friends and make a great discovery.