This town is the oldest settlement in Halkidiki. In antiquity it was known by the name “Sermylia”, while in the Middle Ages it was called Ermylia. The area was first inhabited during the prehistoric era. Ancient Sermyli was located in the area now known as Platia Toumpa. Also in the area was ancient Kallipolis (today an archaeological site). Recently uncovered in the area was a coin dating from approximately 500BC. This area was a monastery dependency of the monastery of Dohiariou Monastery and one of the sights, the old wind mill, dates back to this era. The Church of St. George dates from 1818. During the Ottoman Rule, Ormylia was the landing site for an armed party of refugees from Macedonia, in 1854, designated by King Otto to start a general uprising. However this uprising was squashed by the Turks. This was also the landing site for the heads of the Cretan uprising (1866-1869), Leonidas Voulgaris and Captain Georgakis from Mademi, which also failed and was stanched by the Turks before it even begun. The Town Hall used to house the Primary School, erected in 1909 by an imperial monogram by Sultan Abdul Hamid and dated 1907.