Because Ubaid, Sumer, Akkad, Assyria and Babylon civilizations all emerged around the Tigris-Euphrates, the theory that Mesopotamia is the cradle of civilization is widely accepted.
If you Google for washington monument height, the first listing you see is for a page about the monument at greatbuildings.com. Note that the page mentions that the monument has a base of 55 feet and a height of 555 feet, in keeping with what they call the standard Egyptian proportion of 10:1 height to base.
part of National Mall & Memorial Parks, National Park Service. The Washington Monument dominates the United States Capital skyline as a symbolic tribute to George Washington's military leadership, humble statesmanship, and Presidential fortitude and wisdom.he U.S. Army Corps of Engineers completed the Monumentâs construction in 1884, and along with the Washington National Monument Society, opened it to the public in 1888.