Enter the Villa Bell/Gerhard Ertl Center using the front door, as indicated by the red arrow

Once inside, walk straight ahead and take the stairs on your left up to the second floor:

Once you arrive on the second floor, turn to your left

Turn again to your left and enter the narrow corridor in front of you

The second door to your right leads to the EC²/BIG-NSE office BEL206 (the third one to the PhD student workspace BEL205)