There were many amphitheaters throughout the Empire, however nothing was as grand as the Colosseum. At 189 meters by 156 meters, and standing at 48 meters, the Colosseum encompassed 6 acres of land. Inside those famous walls over 500,000 thousand human lives, and millions of animal lives were put to an end. The Colosseum held the most extravagant events for the most important figures during the time. Everything from one on one combat between gladiators, to animal hunts, to even naval battles, were used to bring entertainment to the masses.
An example of such luxury was the inauguration games led after the Colosseum's completion in 80 AD. It was 100 days of spectacles including having the Colosseum flooded and bringing ships in to have full sized naval battles inside.