Pokémon Ruby and Sapphire/Mauville City

You can do a whole bunch of stuff here, first of all, there is a gym here, which you can battle to get your 3rd badge, in Emerald, you can rebattle this gym after you beat the elite four. You can also get your first bike or you can switch bikes here. There is also the game corner here... Which you can play to win special TMs. Plus, you can get the HM Rock Smash here.