The Crimson Beech, or Cass House, is a private residence in Staten Island's Lighthouse Hill neighborhood designed by Frank Lloyd Wright. Built in 1959 for Catherine and William Cass, it is the only New York City residence designed by Wright and one of only eleven Marshall Erdman Prefab Houses constructed. Ordered as a kit from Madison, Wisconsin, its components were shipped and assembled on site as Prefab #1, part of Wright's late effort to create systematically produced modern homes. The L-shaped house uses broad hip roofs, red brick, cream-colored Masonite, redwood battens, and rich mahogany interiors to emphasize strong horizontal lines. It became a landmark in August 1990.