Skyscraper Day is held annually on September 3. Celebrate this unofficial holiday by climbing or taking the elevator/lift up a skyscraper and by acknowledging the architectural and engineering feats that make such buildings possible. The holiday, which has unknown origins, encourages people to learn more about the science and art of building skyscrapers. Skyscrapers are very tall buildings that define a city's skyline. The term originates in the United States in the late 1880s during the building boom in Chicago and New York. At this time, buildings that had more floors than the surrounding buildings were called skyscrapers. These days, buildings that have have at least 40 or more floors are designated as skyscrapers. Over time, our ability to engineer and construct skyscrapers improved drastically, and now a building must have at least 40 floors to be classified as a skyscraper at all. In crowded urban areas where land space is at a premium, skyscrapers allow us to build upwards rather than outwards, converting a single allotment of land area into 40 or more floors of potential living space. For National Skyscraper Day on September 3, we invite you to join us in taking a long look up.