Set within Bernardsville s highly coveted On the Mountain enclave, this extraordinary residence is a rare offering steeped in architectural history and timeless charm. Originally the carriage house of famed 19th and 20th century architect George B. Post Sr. s estate, this expanded and thoughtfully converted 1890s structure rests on 5.25 private acres, accessed by a long, winding driveway that immediately sets the tone for serenity and seclusion.History echoes throughout the home, where original stonework, century-old trees, and established plantings create a rich sense of place. It beautifully balances traditional authenticity with modern elegance, offering warmth, character, and charm at every turn.At the heart of the home is a dramatic sunken living room, showcasing original stone details and offering an inviting space for both grand entertaining and quiet reflection. With over 5,000 square feet of living space, including a substantial addition completed in 2000, the home features five bedrooms and five full bathrooms, including a private nanny or guest suite with its own bath.Outdoor living is equally compelling, with fall and winter views of the Somerset Hills, an in-ground pool, and expansive grounds designed for privacy and tranquility. Car enthusiasts will appreciate the eight total garage spaces, including two detached garages, a truly rare amenity.Located just minutes from the New Jersey Transit rail station, shopping and the Somerset Hills Country Club, this one-of-a-kind property rewards its next owner with a remarkable lifestyle where architectural pedigree, natural beauty, and peaceful living converge.A pursuit of tranquility. A legacy property. A rare opportunity.