The magic floating rocks of Oasis Springs

The sims I am playing right now live in Oasis Springs.  I built a house for them on the vacant lot there, and when they're not busy with skill building or off at work, I have one of them run around the neighborhood on a collecting spree.  Off at one corner of their neighborhood is this unusual rock formation...

Those three rocks are floating above the ground.  I don't think this is a hint at future expansion packs; EA probably isn't going to resurrect the Harry Potter Makin' Magic pack, but you never really know...