Sweet Cuppin' Cakes Land
From Homestar Runner Wiki
Sweet Cuppin' Cakes Land is where all Sweet Cuppin' Cakes activities go on. The ground is a blue and white checkerboard that can turn into a dance floor. It is always nighttime, and the sky and the mountains can separate from each other to show the page's HTML source code behind them.
Main Page 18 is set in Sweet Cuppin' Cakes Land.
There is also a "Sweet Cuppin' Cakes Land" at Strong Bad's Mount RidesPlace USA in the email "theme park," but it is not shown.