Washington Monument

The Washington Monument is a 554 feet 7 inches tall obelisk located on the National Mall in Washington, D.C. It was built to commemorate George Washington, the first president of the United States, and took over 30 years to complete due to funding challenges and the American Civil War. The monument is made of bluestone gneiss for the foundation and granite for the construction, with the outside facing consisting of three different kinds of white marble. It is both the world's tallest predominantly stone structure and the world's tallest obelisk, and was the world's tallest structure between 1884 and 1889. The monument was completed in 1884, with the internal ironwork, the knoll, and installation of memorial stones finished in 1888.learn more on wikipedia