Amphitheater, in architecture, spacious open-air building generally oval in form. It was originally constructed of wood, and later of stone, and was used by the Romans for gladiatorial combats, fights of wild beasts, and other spectacles. The exhibition area was encircled by seats. The first amphitheater was constructed in 59 bc by the Roman pontifex maximus Gaius Scribonius Curio. The first partial stone amphitheater was built in 30 bc by Augustus, before he became first emperor of Rome. This amphitheater remained the only one in Rome not entirely of wood until the erection of the Colosseum by the Roman emperor Vespasian, whose son and successor, Titus, dedicated the edifice in ad80. The upper part of the Colosseum itself, however, was originally of wood; it was replaced by stone after 223. The example of Rome was followed by all the cities of any importance throughout the Roman Empire. According to a 4th-century document the Colosseum at Rome seated 87,000 persons; modern scholars, however, believe that only about 50,000 persons could be seated. The colosseums of Pozzuoli, Capua, Verona, and Tarragona (all in Italy) are about the same size. See also Circus Maximus.