Located on the islet of Lake Vistonida or Bourou, near the settlement of Porto Lagos, Agios Nikolaos is a dependency (metochion) of the sovereign Vatopedi Monastery on Mount Athos. It is connected to the mainland by a wooden bridge and has a small guesthouse. A small brotherhood, originating from the Vatopedi Monastery, operates daily. On December 6th, the feast day of Saint Nicholas, visitors gather here to celebrate.
The establishment of the monastery is associated with certain traditions. According to the first one, the area around Vistonida was granted to Vatopedi Monastery by the Byzantine emperor Arcadius, and the monastery of Agios Nikolaos was established as an expression of gratitude to the Virgin Mary for his salvation from a shipwreck near Vatopedi.
The second tradition refers to the miraculous rescue of the sick daughter of an Ottoman landowner by an Orthodox hermit who was in the area of Porto Lagos. To thank God for his daughter's rescue, the grateful father donated his land in the area for the establishment of a Christian monastery.