You may want a bit more time in Brussels that just a few hours. Remember it will get dark very early so you may want to have at least a little sight-seeing time in the daylight. There is a neat, little chocolate museum that faces the Grand Place (a few Euros for entry but we got some free chocolate samples). It is very small though and shouldn't take long. Please try to walk to the Sablon and get some Pierre Marcolini chocolate. It is absolutely wonderful and they have neat ice sculptures out front for Christmas. Have a wonderful trip!