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.
remember for more information on the washington monument you can check out the web site at www nps gov wamo also for the other monuments and memorials in dc check out national mall and memorial parks site as wellwww nps gov namaashington monument u s national park service built to honor george washington the united states first president the 555 foot marble obelisk towers over washington d c tickets are required to visit the interior of the washington monument