On the mountainside above the village Mariou at south Rethymnon we meet the cavernous church of Saint Onuphrius (Agios Onoufrios). The chapel celebrates on June 12 annualy. A relatively good dirt road that starts at the entrance of the village leads to the church. The small cave is located at the base of a steep vertical limestone rock that is home to many with endemic chasmophytes (plants that live or cracks and rocks). From this point the views of the villages and the bay of Plakias are unique.
A small elegant stone wall constitutes the façade of the small temple while the remaining part is the natural rock. Inside the church, there is a very simple screen and various icons that pilgrims have occasionally devoted here. What is remarkable in the case of St. Onuphrius is that almost all the temples dedicated to his memory are located in the prefecture of Rethymnon, almost all of them are built inside caves after the saint that spent his life in a cave. We meet an exception in the cemeterial church of village Genna which is not cavernous.