T.C. Kartal Belediyesi Soğanlık Kültür Merkezi is a solid pick if you're after an activity in Kartal. The category has exploded in recent years — bowling, museums, climbing walls, escape rooms, all competing for the same free Saturday. Surviving that competition takes either real quality or a loyal crowd coming back — this place has clearly got one of the two covered. Worth a day of your time.