The world famous Colosseum dates back to the year 70 A.D. when the Emperor Vespasian (69 - 79) decided to build the new grand structure, originally called the Flavian Amphitheatre after the emperors Vespasian, Titus and Domitian, father and two sons from the family of the same name, on the site that was once the artificial lake of Nero, in the Domus Aurea between the Palatine and Esquiline hills.
It was finally dedicated some 10 years later by the Vespasian's son Titus but its completion was oversaw by his youngest son, Domitian in 81 A.D.
The inauguration of the Amphitheatre was celebrated with 100 days of games which included the famous gladiator exhibitions where both men and animals were killed to delight some 50,000 who came to watch.
Other ingenuous games, especially in light of the era, included the staging of naval battles when enormous basins, called naumachias, dug out under the pavement, were filled with water.
The floor itself was made of wood and covered with sand and measured at 84 by 54 meters but the original floor no longer exists whereas some of the underground passageways where the gladiators and animals were kept, are still in tact.
The core of the Colosseum was built in brick and the exterior was finished with a resistant travertine marble.
It measures at 48 meters high, 188 meters long, and 156 meters wide with 80 entranceway arches, 79 for the public and the 80th a private entrance for the emperor, on the ground level.
It consisted of seating which was divided into sections containing a lower podium and an upper podium, a third level, divided into another three sections which consisted of a lower part for the upper class, a middle part for the middle and lower class, and a higher wooden level, added later in around the year 230 A.D., at the top for standing room only for lower class women.
The columns are in Doric, Ionic, and Corinthian.
Because the Colosseum had no roof, the sun was a big factor in terms of being comfortable during day events so engineers implemented an ingenious idea of shading, and cooling as well, with what was called "valerium". Large rope canvases rigged at the top with a hole in the middle curving down to the center to capture the wind that in turn created a breeze for the spectators.
Not only was the architecture of the structure amazing for its time but just as amazing was the order in which the Colosseum seated the spectators. The numbered tickets, indicating both the level and seat number as well as entrance archway number corresponding to one of the 79 numbered public entrances, made for uniform and disciplined seating, a method used even today for stadium seating.
The name, Colosseum is most likely due to the colossal statue of Nero that once stood near it and was used regularly for almost 400 years. Through the centuries it has suffered through earthquakes, neglect, and pillaging but nonetheless, remains one of the most visited and admired monuments in Rome and the world.