This article offers a review of the major results of the Tarquinia Project, a comprehensive study of the site of Tarquinia that the University of Milan began in the early 1980s. The project comprises new excavation at the site, comparison of newly excavated with already-known material culture from Tarquinia, detailed study of buildings at the site, and an analysis of the settlement process. The project also includes the study of a variety of literary sources, including numerous references to the ancient topography of Tarquinia; it produced a series of chronological maps of the ancient settlements in the area that help illuminate the history of Tarquinia and the changing relationship of the city with its territory. The Tarquinia Project also includes speleological, geographical, topographical, geophysical, paleoanthropological, paleobotanical, and archaeometrical research. To provide a better understanding of the fieldwork and to present our most important conclusions, I include in this article some of the most recent, as yet unpublished, discoveries.