Antony H.
Yelp
Sørenga sjøbad is a fantastic public space just near the heart of Oslo and the Opera / Barcode area. Floating jetties right in the fjord allow you to have a safe and enjoyable swimming experience right in the ocean, whilst being in the heart of the city. For the children, there is a beach with sand and shallow water, and for adults, you can dive directly into the deeper water off the jetties. There is also a Olympic sized lap area, which even though there are many people that visit the bathing area, most don't use the lanes/lap pool area. So if you are looking for a place to do laps, without many people in your lane, this is the place to go. The best part about all of these bathing areas, is that is completely free!
Every time I have been there, a lifeguard has been present at the bathing area.
Café's restaurants and a supermarket are all within walking distance, grab yourself, a drink, coffee or ice-cream on a hot day.