For a while, this wall had an Octothorpe and an Octothorpean puzzle. The excellent Boneless Chickens playtested the puzzle and… gently let me know that this puzzle was, uhm, one of the reasons you playtest: it needed improvement. But I didn't improve it, since I figured that the site wouldn't last very long. It's on a building slated for demolition. In hindsight, my laziness seems even more strategically sound: the building's still there (for some/several months), but that mural's gone.
The other revealed-early-since-I-dunno-how-long-its-mural-will-last Octothorpean puzzle might still be there. It's not on my walk to work, so I don't have a chance to check on it so often.