The authors place their work in a regional and theoretical context, providing detailed analyses of radiocarbon dates, structures, features, and artifacts. Authors Hard and Roney, and their contributors, present innovative analyses of plant and animal remains, ground stone, chipped stone, and landscape evolution. Through comparisons with a global cross-cultural probe of hilltop sites and a detailed examination of the features and artifacts of Cerro Juanaqueña, Hard and Roney argue that these cerros de trincheras sites are the earliest fortified defensive sites in the region. Readers with interests in ancient agriculture, warfare, village formation, and material culture will find this to be a foundational volume.