Robert Mills' original Washington Monument plan and the unbuilt colonnade

Architect Robert Mills' early design for the Washington Monument envisaged a taller obelisk-commonly cited as about 600 feet-surrounded by a circular colonnade. Funding shortfalls and political disputes in the mid-19th century halted construction, and the colonnade was never built. The completed monument, finished in 1884, stands at 555 feet 5 1/8 inches, and the phased construction is visible in the exterior masonry.