Patitiri is the harbor and the largest town in Alonnisos. The harbor affords good shelter from the meltemi (the Etesians). You can anchor moor stern-to at the quay to the north of the ferry dock, though space here is limited, or anchor moor on the south side of the ferry quay itself. The bottom is mostly sand and provides good holding. The quay is liable to be crowded during the summer months, while the SW of the harbor is more exposed to westerlies and is crowded with permanent moorings.
The town is attractive and has good shopping but it is relatively new and its architecture is nothing special. The society for the preservation of the Mediterranean Seal, Monachus Monachus or as it is locally known,MOm have an information pavilion in Patitiri which is also the headquarters for their patrol boats.
For many, this is considered the most significant area in the northern side of the island because of its rare wild beauty with beautiful small and secluded beaches. The Megali Ammos is the largest of the small beaches of the bay and consists of white pebbles and fine yellow sand in some places.