136 Swan Sea Lane is a remarkable estate property set on 13.53 acres in gated New Castle, overlooking a roughly 135-acre trophy fishing lake. With 7,709 square feet, 6 bedrooms, 6 bathrooms, and 6 functioning indoor fireplaces, this home offers an incredible combination of size, character, and setting. From the moment you walk in, the home makes a strong impression with its soaring foyer, sweeping iron staircase, arched openings, and elegant formal spaces that are well suited for both entertaining and everyday living. The architectural details, classic finishes, and generously sized rooms give the home a warm, timeless feel throughout. Outside, the stately brick exterior, circular drive, mature landscaping, and expansive grounds add to the private estate feel. With lake views, acreage, and a setting that is hard to find, this is a truly special property for anyone looking for space, privacy, and one of the most unique homes in Madison.