Hidden details in your Springfield?

I put a circle of Easter egg piles in the Wiggum backyard. Ralph is often running around inside the circle. I also have Shary Bobbins flying out to sea, near the plane crash islands. Abe Simpson and Jackie Bouvier hang out on benches behind the senior center. I cobbled together a bus stop outside the community center, since neither ever gets any use. There's a hidden grave, skeleton tree, and small pond behind Fat Tony's compound. The Bart Cave fails to be a secret lair because there's a bright holographic flag marking it. I'm sure I've forgotten some, too.