Was the Colosseum the first stone amphitheatre in Rome?
No. The first stone amphitheatre in Rome was called Amphitheater of Statilius Taurus. It was built in 29 BC by consul Titus Statilius Taurus in the time of the Emperor Augustus. This amphitheatre was quite small and in order to placate the plebs the Emperor Nero built a much bigger, wooden, amphitheatre called the Amphitheatrum Neronis in 57AD. Both of these amphitheatres were completely destroyed in 64AD due to the Great Fire of Rome.