Toba, the name of a simple farmer from an ancient legend in a remote land, was given to a lake, a people, a volcanic crater, and recently a Geopark. The name has many meanings, but to scientists such as volcanologists, geologists, and naturalists, Toba is synonymous with the greatest volcanic cataclysm in human history. This monograph highlights the geologic events leading up to and following the super-eruption that occurred just 74,000 years ago and created Danau (Lake) Toba, the hidden gem of northern Sumatra. Volcanologist Dr. Craig Chesner uses his vast knowledge of Toba to take you on an illustration-packed journey to this geological wonder. Designed for the curious visitor to the Toba Caldera Geopark and the student of volcanology alike, this overview provides a concise account of the dynamic processes that have made Toba the focus of scientific research for over 125 years. The connections between the forces of nature to the stunning landscape and its peoples are continually on display as this narrative addresses almost every aspect of Toba’s geologic origin and evolution, while encouraging global citizens to appreciate its unique status in Earth’s history and explore its many secrets.