Colonnade Row (LaGrange Terrace)

Four surviving Greek Revival marble-fronted townhouses of nine built in 1832-33, linked by Corinthian columns; past residents included Washington Irving, Cornelius Vanderbilt, and John Jacob Astor III. A New York City landmark since 1965 and on the National Register since 1976. The buildings are subdivided into apartments and commercial space today, so they're viewable only from the street.