21 E 81ST Street Just off Fifth Avenue on one of the Upper East Side's most coveted blocks, 21 East 81st Street presents a rare opportunity to own a piece of New York history. Built in 1899, this south-facing, 20-foot-wide, six-story limestone townhome spans approximately 8, 600 square feet and is crowned by a charming mansard roof. Grand interiors feature impressive 12-foot ceilings, multiple wood-burning fireplaces, elegant period details, and an elevator servicing all levels. The parlor floor offers generous entertaining spaces, with sun-filled rooms and a massive windowed kitchen. Above are spacious bedrooms, oversized walk in closets, and a stately library. Crowning the residence is a beautiful landscaped roof deck with views of the Metropolitan Museum and space for dining, lounging, and entertaining. Currently configured as an owner's quadruplex with a separate income-producing duplex, the home offers exceptional flexibility for extended family, guests, staff, a home office, gym, or den. It can also be returned to its original configuration as a grand single-family residence. Set on one of the neighborhood's most elegant tree-lined blocks, 21 East 81st Street is moments from Central Park, the Guggenheim, Museum Mile, and the Upper East Side's celebrated restaurants, art galleries, and Madison Ave shopping.