O’Connor Pool on a cool day in July.

I’d lived in Philadelphia for four years before I learned about our city pools. I knew about some of the private pools (whose fees meant I wasn’t going swimming anytime soon), and I’d cooled off many a day in the fountains along the Ben Franklin Parkway, but the fact that there were six dozen free (and legal) swimming spots in my adopted city had somehow eluded me.

And then, on a sticky, muggy, get-out-of-the-shower-and-immediately-begin-to-sweat day in July 2006, I was riding my bike a few blocks from my then-house when I spied a group of people wrapped in towels, emerging from behind a brick wall I’d passed a thousand times. It had never occurred to me that there might be anything interesting behind that wall, much less something that would fundamentally change my experience of summer in the city.

Philadelphia has 70 outdoor public pools that open during the summer, as well as five indoor public pools that stay open year-round. That’s more free outdoor places to swim than in any of the four US cities that boast larger populations than our 1,547,607. (New York’s got 53 outdoor pools – plus 12 indoor ones that cost money to use – for a population of 8,336,697. LA’s got 47 outdoor -plus 7 indoor – for 3,857,799; Chicago 50 outdoor – and 26 indoor – for 2,714,856; Houston 37 for 2,160,821.)

That first pool I stumbled upon back in 2006, O’Connor, takes up the block of South Street that runs between 26th and Taney. After seven summers of squeezing in visits around an increasingly demanding work schedule, I got to spend this past summer poolside, lifeguarding at O’Connor 35 hours a week. (I may have been a little out of place. My boss Natalia, our “LG2,” or head lifeguard, celebrated her 20th birthday three days after I celebrated my 35th.) I saved a few lives. Mainly I just sat there. It was occasionally boring. But in those moments, I’d look up at the sky and remember that it was summer, that I was outside, that I was getting paid to sit by the water and make sure the kids of our city could enjoy the glory of a swim without it being their last. Life was good.