Park Avenue has traditionally been considered the most expensive residential street in Manhattan, perhaps even in the US. If we were to calculate the avenue's overall property value, it would surpass that of most non-G20 countries' annual GDP. In certain areas of the avenue the price of a square foot can be as high as $4,000, which in meters would mean about $44,000 per square meter.
Park Avenue starts at 135th Street in the borough of Harlem and runs straight down south through Manhattan to Union Square at 14th Street, where it then deviates a bit to the east, becoming Fourth Avenue. In fact, originally it was called Fourth Avenue.
Created at the beginning of the 19th century, the avenue was an open railway track bringing trains in and out of Manhattan along the New York and Harlem Railroad. In the 1850s the section between 34th and 40th Streets was covered with grass and thus became known as Park Avenue. In 20 years, after the construction of Grand Central Depot on 42nd Street, New York's first train station, the tracks between 56th and 96th were lowered underground. In 1936 an elevated viaduct was constructed around what was by then the Grand Central Terminal, allowing cars to circumvent the station while remaining on the avenue. By the time the historic Pan Am Building, currently the Met Life Building, was erected over the Grand Central Terminal in 1962, the entire boulevard from 14th Street to 135th Street was officially called Park Avenue.
Park Avenue is the only other avenue after Broadway to carry both southbound and northbound traffic. Besides residential buildings with some of the costliest apartments in the world, the avenue also harbors the headquarters of several of America's most prestigious financial institutions, such as JPMorgan Chase between 47th and 48th Streets, the Blackstone Group between 51st and 52nd Streets and the Citigroup between 53rd and 54th Streets, as well as the New York offices of many important foreign companies, for example Deutsche Bank, Ferrari and UBS. Famous Park Avenue residents have been American oil magnate John D. Rockefeller, former first lady Jacqueline Kennedy Onassis and conductor Leonard Bernstein.