The NU pool. Our dad, Jim Becker, taught French at NU, so he had keys to the school - and the pool. It might have been against the rules, but he would take our whole family - my mom, my brother John (class of 82), my sister Karen (class of 89) and me (84) - to the NU pool on the weekends.
It was nothing short of delicious to be in the girls' locker room on a Sunday afternoon, absolutely nobody there but us, free to wander around, free to wear OUR OWN SWIMSUITS and not those scary, school-issue suits they'd hand out from behind the counter ("Size?" - the horror), free to do flips off that long blue diving board, free to goof off. Sometimes we'd take our dog Sootie with us. Once, we somehow got a canoe into the pool. Oh, the fun! I was always a little nervous Dr. Duea would show up and we'd be busted and banished.
All three of us learned to swim in that pool. Legions of young ones learned to swim in that pool. First the baby pool, with its gently sloping floor and undoubtedly full of kiddie pee, then the big pool that was deep enough in the shallow end and ocean-deep in the deep end.
In PE, we had to jump in fully clothed, then strip down to our swimsuits and blow up our blue jeans to use as floatation devices. Because - you never know when you might need to strip down and inflate your clothing to survive in a water body.