The Washington Monument is the capital's most remarkable monument, and the world's tallest freestanding stone structure. Inaugurated in 1888, after nearly four decades of construction, this austere white marble obelisk rises from a knoll in the middle of the Mall. It pays homage to the man who was "first in the hearts of his countrymen," and as an indelible symbol for the city that bears his name. Impressive view from the top.