The Colosseum was ordered by the Emperor Vespasian and was built in ancient Rome to please the triumphant returning generals and soldiers and to praise the great Roman Empire. Built during the reign of his son Tumishan, it was one of the landmarks of the Roman Empire. The Colosseum was built on the site of another Roman emperor, Nero's Domus Aurea, which was destroyed by a fire in Rome in 64 A.D. The Colosseum was the place where animals and human beings performed in ancient Rome. The gladiators who participated in the performance had to fight with a wild animal until one of them died. There were also human-to-human fights. According to the Roman historian Dio Cassius, the Romans held a 100-day celebration when the Colosseum was completed, killing 9,000 livestock. The Colosseum originated from the theatre of the ancient Greek period. At that time, the theatres were built near the hill and were semi-circular. The auditorium rose from the top of the hillside. But in ancient Rome, such as the Epidauros Theater, about 330 B.C., designers - "Pyricoletos Polykleitosthe Younger]. People began to use the arch ticket structure to erect audience seats and connect the two semicircle theatres, thus forming the so-called amphitheatrum, and no longer need to rely on mountains. The Roman Colosseum is the largest oval-shaped arena in the Roman Empire. It has a long axis of 187 meters, a short axis of 155 meters, a circumference of 527 meters, a performance area in the center, a long axis of 86 meters, a short axis of 54 meters, the ground is covered with floors, and the outside is surrounded by tiers of stands. There are about 60 rows of stands, divided into five districts. The bottom front row is the VIP (such as elders, officers, priests, etc.) area, the second floor is for nobles, the third area is for the rich, the fourth area is for ordinary citizens, and the last area is for women at the bottom, all of which are seats. There is also a suspended canopy in the auditorium, which is used to shade the sun, and the canopy tilts to the middle for ventilation. These canopies are operated by sailors standing on the top porch like sails.