A monastery of great importance, it is the only Byzantine monastery in the city, still operating. According to tradition, it was built at the exact spot where Apostle Paul taught during his stay in Thessaloniki. It was founded between 1351-1371 by the monk Dorotheos Vlatis, a pupil of Gregorius Palamas later subsequently Bishop of Thessaloniki. It currently houses the headquarters of the patriarchal Institute of Paternal Studies of the Ecumenical Patriarchate of Constantinople. The monastery offers an exceptional view of the city, as far as Olympus mountain, while the sunset over the Thermaikos Gulf is definitely something to remember.