The necropolis of San Germano, situated in the northern territory of Vetulonia, was discovered in the late 1800s by Isidoro Falchi, and investigated by the Archaeological Superintendency of Tuscany between 1967 and 1975. In those years, tumuli 1-4 and 6-8 were excavated and then partially restored. The tumuli, positioned on either side of the Sovata valley, date to between the late 7th and the first half of the 5th centuries B.C. with reuse in the Hellenistic period (second half of the 4th century B.C.).

In 2011 and 2012, Florence University’s Department of Etruscan History, in collaboration with the Superintendency, excavated tumulus 9, situated in the Poggio all’Olivo property.

The investigations continued in 2015 as part of a two-year project, during which tombs 1-8 were restored and the Rocca di Frassinello ‘Necropolis of San Germano’ archaeological area was created. At the same time, two exhibitions of the finds from the necropolis were held, each lasting a year.
In 2017, the excavations continued with attention placed on some unanswered questions relating to the necropolis and due to a lack of in-depth analysis of the archaeological data that was only published in preliminary form. Tumulus 6, tumulus 3, the pit burial 6B, and tumulus 26 were excavated. The latter two in particular provided new data regarding the reuse of the necropolis during the 4th century B.C. and the closure rituals for the tombs in the archaic period.