Chicago is located on the southwest shore of Lake Michigan in the U.S. state of Illinois. Since the mid-19th century, this city has been an important transportation hub and a significant business metropolis. With 2.7 million residents, Chicago is the third largest city in the USA. The ÔÇťWindy CityÔÇŁ is the birthplace of the skyscraper. Skyscrapers still dominate Chicago's skyline today. And when strong winds blow over Lake Michigan, the breeze in the street canyons formed by the skyscrapers can be quite brisk. Some skyscrapers, such as the Sears Tower and the John Hancock Center have observation decks that can make visitors dizzy. The Visitor Welcome Center is located in the Old Water Tower. It is one of the city's landmarks. Those who enjoy learning about technological development and industrial history can view over 2,000 items on display at the Museum of Science and Industry. But there are also hundreds of parks in Chicago, and on the shores of Lake Michigan there are many sandy beaches and large forests. For visitors to the USA, Chicago is also the gateway to the rural areas in the states of Illinois and Indiana as well as the recreational areas found in Wisconsin.