San Martino al Cimino: The Baroque Town Designed as Piazza Navona

San Martino al Cimino, a town in Lazio, Italy, was designed in the shape of Piazza Navona by order of Donna Olimpia Pamphilj (1591–1657), one of the most influential women of the 17th century. Born Olimpia Maidalchini in Viterbo, she rose from modest origins to become the sister-in-law of Pope Innocent X (Giovanni Battista Pamphilj). After dominating Rome, she retired to her Tuscia estates and commissioned military architect Marc'Antonio de Rossi to transform the dilapidated Cistercian abbey of San Martino into a princely residence. The resulting town mirrors the outline of Piazza Navona: a straight side facing Viterbo and a semicircular side recalling the Roman square. Olimpia also ordered Francesco Borromini to design the abbey's new facade and city gates. The town is less known than other Italian ideal cities like Pienza (15th century) and Sabbioneta (16th century), both UNESCO sites, partly due to Olimpia's controversial legacy. She was a key instigator of the Second War of Castro (1646–1649), which destroyed the Farnese duchy. Gian Lorenzo Bernini may have curried her favor by including a palm and lion—symbols of Viterbo—in his model for the Fountain of the Four Rivers, and she likely helped him win the commission. Olimpia died in San Martino al Cimino and is buried in its abbey.