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.
The Eiffel Tower became the worldâs highest monument in 1889 with its 300 metres topping the Washington Monument (169 m). It kept this record for 42 years until the completion of the 319 metre-high Chrysler Building, in New York City in 1930.