It is said that the little church of San Pietro, which is located on the promontory overlooking the Island of Palmaria, was built over the ancient temple of Venere Ericina, or over a slightly less ancient Palaeo-Christian church. In 1256, Portovenere helped Genova to reclaim Lerici from Pisa, and the church was said to have been erected as a thank-you from the Genevans. Built in the genevan-gothic style, the church was finally completed in 1277. The building consists of two parts; a twin lancet bell tower built of chequered black and white stone, and a rectangular building topped with a semicircular apse. The two areas are united by two pointed archways.
The interior features a vaulted wooden ceiling and a presbytery divided into three chapels and covered by a pointed cross-vault ceiling.