On Saturday's evening, when the weather is good, you may find the Warsaw's city center pretty empty. Where did everybody go?
The nightlife moves to river Vistula boulevards. On the left bank you'll find plenty of clubs, cafés, bars and dance floors.
Warning: only for people who enjoy the crowds!
Alternative: cross the river and find as good vibes and much more space to party on the right bank (Praga district)