Complex sentence: It was the first modern dance performed at the Pasar Malam Besar, an annual Asian festival in the Hague since the 50's a cultural centre for the "Indo" community in the Netherlands.
Split into simpler sentences: It was the first modern dance performed at the Pasar Malam Besar, an annual Asian festival in the Hague. Since the 50's this became a cultural centre for the "Indo" community in the Netherlands.