The sands of centuries keep a huge number of burning secrets that still excite the imagination of both scientists and ordinary people. Professional historian and archaeologist Peter James and famous researcher of the extraordinary Nick Thorpe, in the course of painstaking many years of work, have compiled a fascinating encyclopedia of the world's greatest secrets. This book will tell you about the secrets of lost civilizations and lost knowledge, about the majestic monuments erected by the ancients, about the mysterious messages encrypted in myths and legends, about evidence of the existence of extraterrestrial intelligence and mysterious paranormal phenomena. Armed with the most modern scientific technologies, the authors scrupulously analyzed various versions of the origin of the inexplicable mysteries of the world and put forward new, logically sound theories that shed light on many dark spots of human history and the surrounding nature. This encyclopedia will be useful to anyone who wants to expand their horizons and touch the thousand-year-old secrets.