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,
Fontana di Piazza Colonna to the foot of the column of Marcus Aurelius. The source of the water for the fountain of Piazza Colonna was only 67 feet above sea level; like the Trevi Fountain, the Fontana della Barcaccia, and the fountains of Piazza Navona, all connected to the Acqua Vergine, the fountain of Piazza Colonna was unable to jet water high into the air. The original project of Della Porta was to place an antique Roman statue of a sea god, called Marforio, in the fountain, against a background of a rocky grotto, behind which the column of Marcus Aurelius would be seen.