Architecture of Rome huge and majestic Baroque squares (often adorned with obelisks), many of which were built in the 17th century. The principal squares are Piazza Navona, Piazza di Spagna, Campo de' Fiori, Piazza Venezia, Piazza Farnese and Piazza della Minerva. One of the most emblematic examples of Baroque art is the Fontana di Trevi by Nicola Salvi. Notable 17th-century baroque palaces are the Palazzo Madama, now the seat of the Italian Senate and the Palazzo Montecitorio, now the seat of the Chamber of Deputies of Italy. In 1870, Rome became the capital city of the new Kingdom of Italy. During this time,
Piazza della Rotonda the fountain in the Piazza della Rotonda was authorized on September 25, together with a fountain for Piazza Colonna, and two more for Piazza Navona; the fountain for the Rotonda, completed in 1575, was of a chalice-type design, around 3.5 to 4 meters in height, and fed with the Vergine water through a terracotta conduit. Della Porta designed the fountain, and Leonardo Sormani executed it. Due to the slope of the piazza, the fountain is approached by five steps on the south side, and only two on the north. Under the pontificate of Alexander VII Chigi, projects were set afoot