the beginning of the 21st century, Fieldston was one of the wealthiest neighborhoods in New York City. Fieldston is one of a few neighborhoods in New York City that is completely privately owned. The streets and common areas are owned by the Fieldston Property Owners' Association, Inc. which plows the streets, does sewer repair, cares for the trees – of which there are about 1000 – and runs a security patrol as well as other usually municipal functions, such as street repair. Annual dues are paid by the approximately 250 homeowners who make up the Association to maintain the area. Once a year, the streets are closed to non-residents to legally qualify the streets as privately owned; parking is restricted to residents and their guests. Structures Historic district On January 10, 2006, the New York City Landmarks Preservation Commission designated the majority of the Fieldston neighborhood as an historic district. The district contains 252 houses and related structures. Some of the more noted houses, with the year of completion, the architect's name and the architectural style in parentheses: 274 College Road (1926–28, Julius Gregory, Medieval Revival) Gregory designed 42 houses in the neighborhood 4521 Delafield Road (1925, Dwight James Baum, Colonial Revival) received a gold medal from the Architectural League of New York as the best two-story house built between 1926 and 1930 in the U.S. Baum designed 62 houses in the neighborhood 4530 Fieldston Road (1928–29, Gregory, Medieval Revival 4599 Fieldston Road at West 246th Street (1928–29, Baum, Mediterranean Revival 4600 Fieldston Road at West 246th Street (1926–27, Baum, Norman Revival) 4730 Fieldston Road (1929–30, Gregory, Georgian Revival) 5001 Goodridge Avenue (1916, Baum, Colonial Revival) Baum's own residence 5020 Goodridge Avenue (1914–15, Harrie T. Lindeberg, Tudor Revival the residence of Mayor Fiorello La Guardia from 1945 until his death in 1947; later owned and occupied by author Robert Silverberg from 1961 to 1971 4538 Greystone Avenue (c.1924, attributed to R.C. Hunter) features "a turreted tower and a steeply pitched slate-covered roof with a deliberate sag", making it "one of the most charming" in the neighborhood 4600 Livingston Avenue near West 246th Street (1922–24, Clarence S. Stein, Colonial Revival) 351 West 245th Street (1924–25, W. Stanwood Phillips, Colonial Revival) Phillips designed 14 houses in the neighborhood 355 West 246th Street (1911–12, Mann & MacNeille, Tudor Revival) one of the first houses commissioned by the Delafield estate; Mann & MacNeille designed