The Early Byzantine chapel of Saint Nicholas (Agios Nikolaos), the patron saint of the Greek sailors, has given its name to the entire city of Agios Nikolaos. The chapel was built on the edge of Cape Nissi near Katholiko beach, after the seventh century and is one of the oldest ones in Crete. The view to the city and the bay of Mirabello is amazing. The temple has a heavy dome, a large arch and very small openings.
Originally the church had no iconed frescoes, because it was built in the period of iconoclasm, and was decorated with nice geometric and vegetal patterns. Later, after the earthquake of 1303, the church was repaired and decorated with frescoes with Saints, which constitute the second fresco layer. Some of the surviving frescoes depict the Pantocrator, Anna and Joachim and the Ascension.
The location of the temple is not just a coincidence, as it protected the sailors who used the bay Katholiko as the main port in the area for several centuries. In Venetian maps it is marked as Porto di San Nicolo, meaning Port of Agios Nikolaos.