Location: Palm Beach, Florida
Square footage: 11,000
Bedrooms: 4
Baths:5 full, 2 half
Tennis greats Venus and Serena Williams have lived in their shared mansion for a decade and recently added a 4,000 square foot training facility. This enormous estate in the triple-guarded Grand Key Estates features two master suites for the sisters, each in her own wing, and numerous circular rooms such as the foyer, library, and sitting rooms.