We've learned the Oscar winner is listing her 3-acre estate on Tybee Island for a cool $6.5 million, and it just went on the market. Our sources tell us Sandra is selling her Georgia home because she's raising her family on the West Coast, and she doesn't see herself spending much time back East anymore.

As you can see ... the property is amazing, and it's got tons of privacy. There's a private entrance to the beach, and if you don't feel like getting sandy or salty, you can take a dip in the pool. The baller beach house also comes with a basketball court, and a home gym!

The main house is huge ... we're talking 3,360 square feet of luxury surrounded by screened porches, perfect for enjoying those ocean breezes!

You'll probably have tons of visitors -- who wouldn't want to check out Sandra's old digs -- so the guest house will come in handy ... it's 2,848 square feet of fun, with a game room and a crows nest to take in the breathtaking ocean views!