built in the Roman Empire. Originally capable of seating 60,000 spectators, it was used for gladiatorial combat. Important monuments and sites of ancient Rome include the Roman Forum, the Domus Aurea, the Pantheon, Trajan's Column, Trajan's Market, the Catacombs, the Circus Maximus, the Baths of Caracalla, Castel Sant'Angelo, the Mausoleum of Augustus, the Ara Pacis, the Arch of Constantine, the Pyramid of Cestius, and the Bocca della Verità. Medieval The medieval popular quarters of the city, situated mainly around the Capitol, were largely demolished between the end of the 19th century and the fascist period, but many notable buildings still remain. Basilicas dating from Christian antiquity include Saint Mary Major and Saint Paul outside the Walls (the latter largely rebuilt in the 19th century), both housing precious fourth century AD mosaics. Notable later medieval mosaics and frescoes can be also found in the churches of Santa Maria in Trastevere, Santi Quattro Coronati, and Santa Prassede. Secular buildings include a number of towers, the largest being the Torre delle Milizie and the Torre dei Conti, both next to the Roman Forum, and the huge outdoor stairway leading up to the basilica of Santa Maria in Aracoeli. Renaissance and Baroque Rome was a major world centre of the Renaissance, second only to Florence, and was profoundly affected by the movement. Among others, a masterpiece of Renaissance architecture in Rome is the Piazza del Campidoglio by Michelangelo. During this period, the great aristocratic families of Rome used to build opulent dwellings as the Palazzo del Quirinale (now seat of the President of the Italian Republic), the Palazzo Venezia, the Palazzo Farnese, the Palazzo Barberini, the Palazzo Chigi (now seat of the Italian Prime Minister), the Palazzo Spada, the Palazzo della Cancelleria, and the Villa Farnesina. Many of the famous city's squares – some huge, majestic and often adorned with obelisks, some small and picturesque – took their present shape during the Renaissance and Baroque periods. The principal ones are Piazza Navona, the Spanish Steps, Campo de' Fiori, Piazza Venezia, Piazza Farnese, Piazza della Rotonda and Piazza della Minerva. One of the most emblematic examples of Baroque art is the Trevi Fountain by Nicola Salvi. Other 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. Neoclassicism In 1870, Rome became the capital city of