Obelisk in Washington, D.C., U.S., honouring George Washington , the first president of the United States.
Based on a design by Robert Mills (b. 1781
d. 1855), it was built between 1848 and 1884. It is constructed of granite faced with Maryland marble and is some 555.5 ft (169.3 m) high, the world's tallest masonry structure. Inserted in the interior walls are more than 190 carved stones presented by various individuals, cities, states, and foreign countries. It is located on grounds that are a westward extension of the Mall. The top can be reached by elevator or by an interior iron stairway. It underwent a major restoration in the 1990s and reopened in 2001.