The monastery of Panagia Vellianitone is built on the islet of the same name, in front of the islet of Agios Nikolaos and to the left of the port of Gaios.

The church was built by the Vellianites, during the 16th century, on the ruins of a proto-Christian cross, keeping many elements of the previous architecture. According to tradition, in this new church the Vellianites placed the icon of the Virgin Mary (Assumption) that they had brought from the village of Velliani in Epirus, where they came from.

The monastery celebrates on the 15th of August, where every year a large number of believers visit the islet of Panagia to worship.