Borough (pop., 2007 est.: 1,373,659), New York, New York, U.S. One of New York City's five boroughs, it is the only mainland borough, and it is connected to Manhattan by a dozen bridges and railroad tunnels and to Queens by the Robert F. Kennedy (formerly called Triborough), Bronx-Whitestone, and Throgs Neck bridges. The site was called Keskesbeck by the Indians who sold it in 1639 to the Dutch West India Company. The borough was a part of Westchester county until 1898, when it was incorporated into the city of New York. Though primarily residential, much of its more than 80 mi (130 km) of waterfront is used for shipping, warehouses, and industry. It is home to baseball's Yankee Stadium. It has an extensive park system and includes the Bronx Zoo and the New York Botanical Gardens.