This book offers a new interpretation of the site of ancient Tainaron, the mythological entrance to the Greek underworld, by presenting a complete overview of its roles, functions, and significance throughout history. Located on the southernmost tip of the Mani peninsula in Greece, Tainaron is surrounded by a vast stretch of Mediterranean Sea. The perceived remoteness of the site, coupled with its stark, barren landscape, lends itself well to Tainaron’s most famous role as the entrance to Hades. Despite its fame and alluring reputation, Tainaron remains largely misunderstood, since its various functions – a sanctuary to Poseidon, a Hellenistic mercenary gathering place, and a marble quarrying site – are often examined in isolation rather than holistically. Gardner argues that Tainaron’s various roles are, in fact, closely intertwined and directly related to its perceived liminality. Through a comprehensive examination of the historical, epigraphic, and archaeological evidence, this work situates the site of Tainaron within the historical narrative of the ancient Mediterranean. Tainaron in Classical Antiquity appeals to students and scholars in the fields of Classics, Ancient History, and Classical Archaeology, particularly those interested in sacred landscapes, sanctuaries, and the history and archaeology of Lakonia.