Three Shades of White It is, after all, the tallest all-stone structure on the planet. But upon further inspection, while it may be all stone — marble underlain with blue gneiss and granite — it is definitely not all one color. It's actually three.

The Washington Monument actually appears to be two distinct colors, though it is composed of stone from three different quarries. The visible "color line" occurs about 150 feet up the 555-foot structure. This is because construction was famously halted for 22 years (from 1854 to 1876) due to a lack of funds and the onset of the American Civil War. When work finally resumed, the original quarry in Maryland was no longer available, so builders sourced marble from a different quarry in Massachusetts and later a third quarry back in Maryland. Initially, the new stones looked fairly similar to the old ones, but over a century of weathering and exposure to the elements, the marbles have aged differently. The bottom third is a noticeably lighter, more "creamy" white, while the top two-thirds have a slightly different greyish or tan tint. This "mistake" has become a permanent historical record of the monument's troubled birth. If you look closely at the base, you can even see a third, slightly different shade where a different set of stones was used for the foundation and first few rows. Far from being a flaw, the color shift is now considered a vital part of the monument's character and a reminder of the nation's own period of reconstruction.