"The Underworld: A Mirror of Life Beneath the Surface" - a book written by the famous American writer Thomas Wallace Knox, explores and reveals the secrets of the underground world. The author takes the reader step by step through the labyrinths and catacombs, telling about the diverse world that exists under our feet. The book is full of interesting facts, exciting stories and incredible discoveries that will help you feel the depth and mystery of underground life. "Underworld" is not only a guide to the unknown, but also a mirror that reflects the secrets and secrets of life in the depths of the Earth.