The Monastery of Vlatadon is situated on the Thessaloniki acropolis in the quarter of Ano Poli. It was founded in the second half of the 14th century, and as the only monastery in Thessaloniki, it has been inhabited by monks till today. In the midst of the monastery premises, there is a small byzantine church with remarkable frescoes (yet they were damaged by Ottoman Tusks). In the time of their rule, the church was used (like most Thessaloniki churches) as a mosque but then it was rebuilt in the 18th century. In 1983, the mural paintings inside the church were renovated, uncovering frescoes dating back as early as the 11th century - therefore the little church had stood there already before the monastery was founded.

The monastery is the site of the Patriarchal Institute of Patristic Studies, the only institution of its kind in the world. It operates a vast library in possession of a collection of remarkable mediaeval manuscripts that have been digitalized. Every year the institute hold a conference on the history of Thessaloniki in the Byzantine era.