Eggman's Hideout

In the "Dimension" saga, Doctor Eggman is shown to have a secluded hideout located within a relatively close vicinity of Leaf Forest. This hideout shelters some of the machinery he has set aside, such as spare Egg Robos, a few getaway vessels (Egg Carriers, for example), and presumably much more. Considering that the Doctor usually keeps most of his prized and most dangerous machinery aboard his orbital space station, the Death Egg, it can be assumed that his hideout is mainly for secondary storage and the occasional retreat, should any of his preferred locations become no longer safe. For a short time, Eggman's now-abandoned hideout (in light of his apparent death in Zim's dimension) becomes a refuge of sorts for the alliance of heroes during the Xevian invasion(s); specifically, Sonic and company break in to use a spare Egg Carrier for rescuing Zim from Tak—and later on, the entire alliance retreats here after the Mushroom Kingdom is revealed to have been conquered by the Xevians.