Even if you’re not a huge fan of lap swimming, indoor pools are often really special examples of national architecture—my favorites are from the first half of the twentieth century—and it’s surprisingly interesting to observe the pool etiquette of different cultures. Italians, while somewhat impatient and in-your-face on land, are incredibly courteous and respectful of relative speed in the water; they’re gracious and accommodating if you need to pass them. In Milan I always make a point to go to Piscina Cozzi, which had a huge Maurizio Cattelan mural on the back wall featuring a tacky Ophelia in red lipstick. It was there in October of last year, but I think they’ve since taken it down, which is a shame, but apparently he swims there, too.