The Lands of Erathil
The Gladiator Arena is a large, round arena meant for fighting.
Around the middle of the arena is an unstable fortification which can be climbed for an advantage in high ground.
The arena seems to attract numerous followers to each event, even multiple times a week – leading to the belief that Illguard is quite a large settlement.
After the Cataclysm
The arena seems to have been repurposed as a prison and as guard quarters.