The Main District is a region in Omnitopia. It is the main area of the region, a series of space platforms connected by catwalks and force fields. From here all other areas of Omnitopia are accessed via hatches in the floor.
Spherebots guard access to portals between platforms; the Dog must go outside and destroy the Spherebots to open the way. Additionally, after visiting Ruffleberg's Lab, some of the formerly inactive connections between platforms will activate, allowing easier travel through the Main District.