They are rare and some are heated(this one is not). Then again, central AC is often installed in new buildings here today. I tell people that put a toe in and cringe, it's warmer than swimming in the harbor.
I was surprised how much this pool adds the powerful element of water around you. The pool is more of an accessory to an outdoor area to sit and talk, or read, or just to gaze at the water and think. It constantly reflects changing angles of sunlight throughout the day and evening. Fascinating light.
As far as swimming, this one has more dogs in it than people. Andre', the famous harbor seal lived two doors down. He would have loved this.