It Doesn't Get More Visible
If you're going to put something in 6-foot-tall letters on a landmark visible for miles, it's best to check your spelling two, three, or even four times before painting it on.
Case in point: This water tower in Stoughton, WI. It was missing the "T" in "STOUGHTON" on one side.
Luckily, the mistake didn't last long -- several eagle-eyed passersby let the painter know about the error immediately. The misspelling was quickly fixed.