This square, situated close to the Grand Bazaar on top of the third hill of ancient Byzantium, where the Ottomans built their first palace, is a hive of activity, where the spiritual mixes with the intellectual, both of which are caught up in the relaxed shopping atmosphere that spills over from the Grand Bazaar. Take a seat on the shaded terrace on the square and observe the street spectacle unfolding before you. The 16C Beyazit mosque, which dominates the scene, is flanked by the university (1866). The mosque's former medersa is now home to the Museum of Calligraphy.