Luckily, the water quality in the city harbour is tops and everyone in the city swims there. Except it's not officially permitted, so now you know. However, this spot, originally built for kayaking, makes for a perfect urban beach. On a sunny day, slacklines fly up, BMX crews show some tricks and there's always a guy with a speaker.
Practical info: the floor is made of wood, so bring your thicker towel.
Water: ranges from 16 to 18 on average and 20 if you win lotto.
Kalvebod Bølge, 1560 København V, Denmark