Akanthos was the most important city and harbour of NE Chalkidiki. It was founded in the middle of the 7th century B.C. by colonists from Andros, on the site of a prehistoric settlement. The city extends on a ridge almost 600 m. SE of modern Ierissos.

Sections of the fortification walls of the city are preserved, including an impressive part of the acropolis; the whole area, though, is covered with architectural members and buildings of the Classical and, mainly, the Hellenistic period.

The extensive cemetery of the city, containing some 13000 graves, lies on the shore and was used from the Archaic period (7th, 6th centuries B.C.) until the 17th century.