Ben
Google
I'm blown away that not more people visit this place. For 2 euros you can visit a piece of history, crossbowman's guild that has been around since 1381. Jam packed with historical items, the Guild members will be glad to show you around. Please go visit this place!!
They are open Tuesday between 1 and 5 pm, and Thursday evenings. You can email them for more info. On Thurs, you might even get a chance to shoot a crossbow yourself. Enter via the main entrance to the Belvue Museum, through the courtyard directly in front of you to the gates on the other side. Then turn left and follow the road down to an unassuming green gate.
Seriously, this was unexpectedly awesome.