Okay, so it seems obvious that the next photo challenge should be Thanksgiving, as we're about to turn the page of the calendar into November.
But the Jane Voohees Zimmerli Art Museum in my old stomping ground, Rutgers University, has a theme for several exhibits and lectures of and on water. I think it might be intriguing to dovetail into that. I wish I was there to check the exhibits themselves out.
So, any preference? Water would be a challenge for me right now, as November is not a watery month in the desert, but that would definitely increase the challenge aspect.