Grand Bay Tower is a bayfront condominium at 430 Grand Bay Dr in Key Biscayne's gated Grand Bay enclave, completed in 1999 beside Grand Bay Residences and across from the Ritz-Carlton Key Biscayne. Consistently described as a boutique building of roughly 100 residences, Grand Bay Tower is known for some of the largest floor plans on the island: listed two- to four-bedroom residences run from about 2,840 to 3,950 square feet, with a 9,600-square-foot penthouse. Residences feature high ceilings, multiple terraces with bay, skyline and ocean views, corner lines with three balconies, chef's kitchens with center islands and breakfast nooks, marble floors in living areas, en-suite bedrooms and, in larger plans, maid's quarters with a full bath. Amenities include a bayfront pool and spa, fitness center, tennis, a clubhouse with media and recreation rooms, 24-hour gated security with doorman and concierge, valet and assigned parking, beach access through the Grand Bay beachfront, and bike and storage rooms. Recent asking prices have ranged from about $3.4 million to nearly $25 million for the penthouse, with monthly dues reported around $3,200 to $4,400. The tower sits on the west side of Grand Bay Drive at the southern end of Key Biscayne, minutes from Bill Baggs Cape Florida State Park and the village center along Crandon Boulevard. Not to be confused with Grand Bay Residences at 445 Grand Bay Dr. Browse Grand Bay Tower condos for sale and rent with REHUB Miami.