I've put this in a previous post but can't find it.
I drank the best beer I've ever had in my life in Bruges. A nice American fella' gave me these exact directions whilst drinking in Bar Delirium in Brussels.
If you're standing directly in front of the big clock tower in the main square - head towards the road up on your left.
About 100 yards up look to your right and there should be some alley ways. There will be one that is painted red, or it has a red boarder.
Go down there to the bottom and there is a little wooden bar with a fire inside - you have to go up some wooden stairs to get there.
Order a house beer and be prepared to have your world changed. They served it with little blocks of cheese.
It's called something like Gorre or De gorra'.
You won't regret it