Shelbyville Bluffs
Wikisimpsons - The Simpsons Wiki
The Shelbyville Bluffs are located near the Shelbyville/Springfield border. They are clearly visible from Springfield.
The boys of Shelbyville once tried to paint "Springfield Sucks" on the bluffs for all of Springfield to see. However, their plan was thwarted by Bart Simpson, who instead wrote "Springfield Rules Suckers!" ("Lemon of Troy")