This Penthouse sits atop a 1920-era building perching directly over New York’s well known High-Line garden promenade. The apartment, designed for two avid art collectors, is defined by a central rectangle with moving walls for art display, with ancillary rooms connecting off of it. The front of space houses an art foundation’s offices and a long, skylit gallery, which can be subdivided off from the family areas of the dining, kitchen and living room.