Grand Cay Estates Highland Beach, Florida. Hidden within the Boca Highlands Marine and Beach Club community in the tiny hamlet of Highland Beach, is Grand Cay. This small enclave of less than 20 homes is a showcase of Mediterranean waterfront living. Courtyard homes, each with its own private dock located within a protected harbor, had all the amenities, as well as access to its own private beach club. Its Highland Beach location offers all the benefits of small town living, only a few short minutes from the excitement of Boca Raton. Lot #01 Past Project Lot #03 Past Project Lot #04 Past Project