As of today, listings are live for developer/architect Cary Tamarkin’s 555 West End Avenue. The project converted the former Catholic St. Agnes Boys High School into a 13-unit luxury condo. Not only does it retain the facade’s original 1908 English collegiate- and Gothic-style elements, but the interiors benefit from the historic structure’s 12-foot ceilings and oversized windows. The most impressive of these residences is undoubtedly the solarium penthouse, carved out of the school’s one-time gymnasium. Listed for $18 million, the incredible space has a soaring 20-foot-high vaulted glass ceiling and an enormous, floor-to-ceiling arched window wall.