††††A skyscraper is a building consisting of many storeys.
The first skyscraper was the Leitner Building, erected in Chicago in 1879. By 1883 skyscrapers were constructed with an iron frame for extra strength, and by 1889, with a steel frame.
New York's Empire State building, completed in 1931, has a height of 381 metres. It remained the tallest building in the world for over forty years, until it was overtaken by the World Trade Center in 1972 (also built in New York). Today the tallest office building in the world is the Sears Tower in Chicago in the United States. It is 443 metres high, with 110 storeys. It is served by 104 lifts and 18 escalators.
