Dome City
From the Super Mario Wiki
Dome City is a location in the Super Mario World television series. It is the home of Oogtar the Caveboy. Like the map screen for Yoshi's Island, it's a cluster of domes, many of which are buildings.
The domes come in all shapes, colors, and sizes. Mario's house has a moat and windows, as seen in the picture. The inside walls are the same as the outside, a smooth unknown material.
