Every summer is the time where we get to dip in the sea and have lots of days to swim for free in the warmest time in Norway which is quite cold by asian standards. However, "deilig" meaning nice for Norwegians as they get to sun tan without getting that cold !
Apart from the famous naked beach Bygdoy, there is a more different family kinda beach on another side called Hvervenbukta and it's easy to get there from the bus stop nearby the opera house and it is not a far walk as compared to Bygdoy. However, it is not a frequent bus.
Check out the video on how to get there and if you are daring enough, try to
jump off the bridge which the located would be on the way there!