Besides Geraardsbergen, you can also visit a lot of other interesting cities
like Ninove, Aalst, Brakel, Oudenaarde, Ronse, Edingen and Lessen, all at about 10 or 30km.

For those who don't mind going further, you have Brussels, Gent, Ath, Doornik and Kortrijk
and at about 80km you can even go to the Belgian coast.