Monopole is a large, highly advanced metropolis that appeared in Sonic Riders: Zero Gravity and serves as the main setting of the game, and is described as "the famous city of the future". It is given a name in the Japanese media of the game, but it is not given a name in English-language regions.
Monopole is shown to be a very advanced and extremely high-tech city area. It has tube-like roads with hover-cars, colossal and awe inspiring building structures and robot-workers walking on the streets, making it resemble something taken directly out of the future.
In line with its imposing stature, Monopole features a large variety of areas, such as the bustling and prosperous metropolis of Megalo Station, the chrome canals of Aquatic Capital make it look like a shining new Venice and ecospheres containing an abundance of flora like Botanical Kingdom.
The city of Monopole is much more streamlined than Metal City was. It functions more as a regular city in the future with mass transport by train, parking lots, gardens, and freeways compared to how Metal City functioned like a giant Highway.
The region's reliance on robotic technology is exploited by Dr. Eggman during Sonic Riders: Zero Gravity. Monopole is also known for housing the headquarters of MeteorTech, a security manufacturing company which is owned by Dr. Eggman. As shown in Sonic Riders: Zero Gravity however, this shell company is merely front for Eggman's Eggmanland project; by using the city's dependency on technology, the scientist saturates Monopole's industrial economy with his own SCR-GP model robots–intending to later seize control from Crimson Tower once his machines have thoroughly infiltrated society and then use them to take control over the city and possibly the world. His plans however became endangered when the Arks of the Cosmos caused his robots to run amok on their own and was ultimately foiled by Team Sonic, Amy Rose, and the Babylon Rogues.
Monopole is shown to have a number of distinctive locations such as:
- Megalo Station/Nightside Rush
- Botanical Kingdom/Snowy Kingdom
- MeteorTech Premises/MeteorTech Sparkworks
- Aquatic Capital/Tempest Waterway