The concept of New York City's "Midtown" has evolved a great deal since the first settlers arrived in the early seventeenth century. The center of town moved steadily north over the following centuries. Modern Midtown encompasses everything between 14th Street and 59th Street, and includes three of the city's major transportation hubs – Pennsylvania Station, Grand Central Station, and the Port Authority Bus Terminal. It features the city's finest shopping and entertainment, and most well-known skyscrapers―the Empire State Building and the Chrysler Building. Midtown also includes such landmarks as the United Nations, Rockefeller Center, St. Patrick's Cathedral, and the New York Public Library. The heart of midtown, between Lexington Avenue and Eighth Avenue, has changed the most over the last century, while to the east of Lexington and the west of Eighth, you can still find many original nineteenth century buildings. The writer O. Henry once said about New York City: "It'll be a great place if they ever finish it." Midtown Manhattan is a great place precisely because it is ever a work in progress, a dynamic and vital part of the city that offers a colorful and exciting mixture of old and new.