We had a 120m x 50m public pool around as a kid. It was fantastic, more like swimming in a lake. It got replaced by two stainless steel contraptions (one regular 50m pool and one "play pool"). The play pool has many features that are supposed to be "fun" for kids.

But I remember the thrill of swimming to the centre of the pool and being away from everything. It felt like a real achievement and a little unsafe but in a good way.

I suppose it wasn't easy to maintain and not as "safe".