This challenge is giving me an opportunity to go through my many photos. It’s made me realise how many photos I have of doors! I took this one, probably the oldest door in my “collection,” in the walled town of Laguardia, in Rioja! I don’t know what was behind the door but it might have lead to the caves below the town which are used for storing Rioja wine. I can’t be sure but I suspect this might be one of the oldest doors I’ve photographed.