The workshop will take place at the Faculty of Engineering of the University of Mons (Rue de Houdain 9, 7000 Mons, Belgium). [Google map link] Note that "Mons" in Dutch is "Bergen": if you arrive at the airport in Zaventem (Dutch-speaking part of Belgium), this can be useful to know.
It is within walking distance of the train station (15 minutes). Here is a map:
If you come by car, you can park for free outside the "ring" around the city of Mons:
Since the city of Mons is relatively small, any hotel within the city is fine (see, e.g., Booking.com for a comprehensive list of hotels).