In reply to Giles Davis:
The new topo of Freyr (brandnew - for sale since mid january) costs about 25 euro and can be bought across the street from the parking spot at freyr, at the frituur (bar for eating chips).
Freyr is the biggest (and I think) most beautiful crag in Belgium.
Dave's nice as well, but not as nice/big and you won't find the topo that easily.
On good weekends (weather wise) Freyr can be crowded so Dave could be a good backup plan