This textbook explores the mystery of human origins in the Arabian Peninsula, the lost Southern Crescent where humanity took its first steps toward civilization. Under Arabia's surface of sand and stone lies a primordial realm of rolling grasslands, freshwater lakes, and river floodplains. This book aims to restore a critical missing chapter in the prehistory of our species that played out in this forgotten place of plenty. The author has carried out more than twenty years of fieldwork in Yemen and Oman, weaving his research together  into an unorthodox tapestry of archaeology, environmental science, genetics, and Middle Eastern mythology. This volume peers beneath Arabia's abandoned deserts, revealing a land that once served as a bridge between prehistoric worlds. This textbook is suitable for undergraduate and graduate students as well as all readers who are interested in learning about Arabian prehistory.