They adapted the Greek theatre by expanding to semi-circular theatres into an Amphitheatre, (“amphi” means “double” or “two”) by placing two theatres facing each other to construct and enclose an oval space, called the arena. The arena was utilized as a stage for Roman entertainment such as gladiator and animal fights, public executions, and sometimes even naval battles. All in all, the Colosseum served as a very useful and important innovation to the Romans.
The Colosseum contains many important inventions that were vital in the growth and evolution of Roman architecture. It contains a series of 80 ached entrances repeated across the entire face of the building. The arch shape is repeated throughout the building, from the sub-floor to the top, in regular rhythms. The arch became famous and well-known all around the world, due to it being used numerously all around the Colosseum. Since the Colosseum became very famous, the arch became more famous as well.
Finally, due to the invention of Roman cement and concrete, the Colosseum and many other Roman structures are still standing today. The invention of concrete has helped the Romans create more durable buildings, and is even used to create many long-lasting buildings