Early November is the most underrated time to travel in southern Europe

Just back from a week in Seville and Córdoba. Around 22°C most days, no queues at the Mezquita, hotel prices about half of what I saw quoted for May. The downside is shorter days and a couple of places running reduced hours, so you do need to plan sunset around dinner. Where's your favorite shoulder or off-season destination, and what's the catch nobody tells you about?