Believed to have been founded around 1351 on the place where Paul preached in Thessaloniki, this secluded monastery blends fascinating history with some of the best views of the city. Listed by Unesco, it is thought to have been significant for Hesychasm, a controversial movement whose foremost 14th-century proponent, St Gregory Palamas, is depicted in a fresco here. You can explore the grounds, the ancient church, a museum of icons, and an aviary filled with peacocks.
A now-lost imperial chrysobull (gold-sealed decree) indicates the Byzantine Empress Anna Paleologina endowed Vlatadon, which still preserves a rich archive of documents dating to the 15th century.