Excavations undertaken in the area close to the church of SS. Nazario e Celso in the middle of the last century had revealed a structure north of the church. Divided into several rooms it was of uncertain function but datable to the second half of the 3rd century A.D.

Later campaigns undertaken by Nino Lamboglia in 1959 and 1963 in the area south of the church, had revealed the existence of at least two phases of the building, generically dated to the late Romanesque (13th-14 century) and pre-Romanesque periods, overlying an early medieval structure which it is suggested may be the first religious complex on the site, dedicated to saints Nazario and Celso, 1st century Christian martyrs. Their cult spread in Liguria from the 5th-6th century onwards under the Ambrosian influence on the Ligurian dioceses, and in particular, on that of Albenga.

Recent excavation campaigns (2005-2009) documented the use of the area on the south side of the church as a cemetery, with the discovery of its perimeter structures and of 38 burials all with the following characteristics: inhumation in earth graves, the grave edges reinforced with stones, the graves marked on the surface by heaps of stones, west-east alignment, almost total absence of elements of clothing and personal ornament.

The cemetery dates to two periods: an earlier phase (cemetery 1), datable to between the end of the 13th and the end of the 14th century (presence of archaic majolica and archaic graffita tirrenica), over which a new cemetery was laid out during the 16th century (cemetery 2), which partially overlay and partly disturbed the earlier phase. The skeletal remains are being studied by the Biology department of Pisa University.