My grandpa grew up in a house with a decorative cast-iron vent hole in the dining room ceiling, to let heat into the second-floor bedroom, through the floor. I never realized what a weird thing that is, a hole in the floor! My brother has the house now, and is restoring it, so I can't say I miss it, exactly - but I do miss tossing things down that vent hole onto the unsuspecting adults! My brother once put his whole leg down it and scared the bejeebers out of our little cousin. That makes four generations playing with that thing (so far)