Stonehurst, The Robert Treat Paine Estate, is a mansion in Waltham, Massachusetts. The mansion is situated on 109 acres of conservation land. The property is listed as a National Historic Landmark and is owned and operated by the City of Waltham. The facility is available for private meetings and social functions, though it also has guided tours and educactional programs. The function rooms and two outdoor porches. This historic property is an ideal facility for weddings, luncheons, business conferences and holiday parties. The spacious, meticulously restored public rooms can comfortably accommodate groups up to 150 people. Ample parking is available and the first floor is accessible.