Summer is here and there are plenty of things to do which combine sunseeking and excercising your brain so it’ll be shipshape when September comes around, as you know it will. Here are some suggestions that should get you throught until then. Break the chains This year’s Keti Koti Festival takes place on Museumplein, with music, dance, and a lot of food (for thought). The official remembrance ceremony marking the abolition of slavery at Oosterpark, which kicks off a year…