Originally built as a private retreat, the idyllic Rosario Resort & Spa is now open to the public in an incredible natural setting.Rosario Resort & Spa has 127 guest rooms, all offering spectacular views of the pristine and beautiful Cascade Bay and the Marina.The original mansion boasts 6,000 square feet of teak parquet floors and a music room that features a Tiffany chandelier and a working 1,972-pipe Aeolian organ. It's one of nine buildings spread out over eight acres on the evergreen covered hillside.