The Castellaraccio di Monteverdi is located on a hill along the right bank of the Ombrone river, in control of a collapsed medieval bridge that connected it to the nearby Sasso d’Ombrone and along the primary route between the coast, Monte Amiata and Chiusi. Remembered in written sources from the 12th century, the site seems to have been abandoned during the late 13th century. Belonging to both the possessions of the Ardadia Ardenghesca (Civitella Paganico) and the monastery of San Salvatore a Giugnano (Roccastrada), its decline was perhaps due to the birth of the Franco-Paganico village by the Republic of Siena.

Archaeological research was started in 2018 as part of the IMPERO Project (Interconnected Mobility of People and Economies along the River Ombrone), promoted by the Department of Classics of the University at Buffalo (SUNY) in collaboration with The Cooper Union for the Advancement of Science and Art and Michigan State University.

The excavation campaigns showed a more complicated settlement sequence in the medieval period than suggested by the analysis of written sources only. Furthermore, the recovery in a secondary position of a series of finds from the late Etruscan / early Republican era would seem to hypothesize the presence of a high-altitude settlement of the classical era.

In addition to traditional archaeological research, the team also added LIDAR analyzes and surface surveys to understand the real urban layout of the medieval settlement.