GARDENSIDE — once known as Cara-Mia — is truly one of Southampton’s storied estate properties. The three-story Shingle Style estate consisting of some 9,000 square feet, for many years the home of Madame Jacques Balsan, the former Consuelo Vanderbilt and Duchess of Marlborough, has been immaculately reminted by award-winning designer Thomas Pheasant and master builder Ed Bulgin. An entry with original 1873 parquet oak floor opens to a firelit living room, knotty-pine-paneled library, and formal dining room with four hidden butler pantries adjoining a state-of-the-art kitchen. A covered sitting porch with sliding windows leads to the rose garden and lily pond. Second- and third-floor highlights are a sumptuous master suite and six additional ensuite bedrooms. Located in the historic estate section, the private grounds of some two acres afford a world-class formal English rose garden, three additional masterfully executed gardens, courtyards of antique Belgian block, a clay tennis court, bluestone terraces, and a 45-foot swimming pool.