The Hof is a tucked-away complex of red-brick monastery buildings just behind the Voorstraat. It is famous less for what it looks like than for what happened in it: the First Free States Assembly of 1572, when the rebellious towns of Holland declared their loyalty to William of Orange rather than to the Spanish crown. The museum inside, opened in 2015, tells that story and the wider story of the Dutch Republic with films, interactive displays and a few original artefacts including portraits of the men who attended.
Even without the museum, the cloister courtyard is worth a few minutes — a quiet medieval space hidden behind a working town. The complex is also home to the regional archive and a small chapel that is sometimes open. The museum is part of a combined ticket with the Dordrechts Museum and Huis Van Gijn.