Each arena is a circular replica of the ancient Roman colosseum. The exteriors are ornately decorated with shining white marble, and every arch is filled with a nearly transparent glass window that makes the colosseum glow in the sunlight. Io's Colosseum, the largest of all is 525 ft in diameter and has two tiers of seating, including executive suites at floor level and between the upper and lower tiers. It has a capacity of 40,000 people. There are also large jumbotrons located above the top stands at the cardinal points to magify the action for the nose-bleed fans, show instant replays, and the time remaining. A grand torch burns over an arch on the main walkway leading into the stadium. The seven smaller arenas surrounding Io are just over half its size. They are 300ft in diameter, have a single, steeper tier, and can support about 20,000 spectators. But they are no less beautiful.
The fighting ring is a large, circular concrete slab. It has a 100ft diameter (33.3 yards) and is four feet thick. When fighters enter the ring, they use metal steps located on opposite sides of the ring. These steps are wheeled away by the officials before the match so they cannot be used during the fight. Opponents also enter through gates on opposite sides of the ring. The ring is also held together by intense magnetics and artifical gravitational bonding, so it cannot be cracked or destroyed. The floor between the ring and the stands extends an extra 15 feet on all sides. It is padded with foam tiles that are a different color in each stadium.
The stands are protected by an invisible shield that utilizes stolen technology similar to Juin kinetic armor. The shield has a 150 ft ceiling that you can't fly over or through. If you some how leave the shield perimeter during a match, it will count as a ring out and you will be disqualified. The shield absorbs energy and if a person touches it, it will absorb their impact and repel them three inches. It won't hurt physically.