Pavia's attractions divide neatly into two halves: the medieval city within the old walls, dense with Romanesque churches and Visconti-era towers, and the Certosa di Pavia monastery a short drive north. The university, one of the oldest in the world, gives the city a population of students who keep the bars and osterie busy into the night. Allow a full day for the city and either a morning or afternoon side trip to the Certosa.