If an event is not yet sold out, you can buy tickets at the box office before the start of the event. The box office opens 90 minutes before the event and is located at the front of the building (see number 9 below). Do not buy tickets on the street! There's a chance they are forged and you will be denied access to the venue.
ATTENTION: There is an additional service charge of 2 euros per ticket when purchasing tickets at the box office.