Today's library is a concrete hulk, not nearly the beautiful building you'd expect from such a historic site, but its background is fascinating. Citizen militias used to meet here: the 'hand-bow' (handboog) militia in No 421, and the 'foot-bow' (voetboog) militia in No 425, which also served as headquarters for the Dutch West India Company.
Now you know where the names of the nearby streets Handboogstraat and Voetboogstraat come from. Their firing ranges at the back reached to Kalverstraat.