Eggman's bunker is an enforced metal shelter located in the jungle on Seaside Island. It is designed to withstand anything, including zombie apocalypses, robot uprisings, extinction event asteroids, and misguided people handing out pamplets. Its only entrance being a small bast door, the bunker itself includes the basic necessities, such as light, tables, chairs, bunk beds and rations.
When an asteroid was on collision course with the earth, Eggman planned to ride out the impact in his bunker (after Orbot and Cubot cleaned it up). To earn a profit from this, Eggman offered spots in his bunker to the villagers which he sold to those he deemed most worthy. However, Eggman got trapped in the bunker after a fragment from the asteroid (which Team Sonic destroyed) blocked the exit.
In an attempt to occupy Sonic to ensure the success of Eggman's latest scheme, Cubot tricked Sonic to do a Meh Burger delivery run to the bunker. There, Cubot stalled Sonic from inside the bunker until Sonic knocked down the door and made Cubot pay for his delivery, before heading out on the road again.