Kastanas (Greek: Καστανάς, [kasta'nas]) is a village of the Chalkidona municipality. Before the 2011 local government reform it was part of the municipality of Koufalia.[2] The 2021 census recorded 483 inhabitants in the village.[1] Kastanas is a part of the community of Prochoma.[1]
The population of Kastanas consists mainly of Greek refugees from İzmit, but there are also smaller numbers of Sarakatsani and Greek refugees from Bulgaria.[3] The village was formerly known as Kara Oglu (Greek: Καρά Ογλού, [ka'ɾa o'ɣlu], from Turkish: Kara Oğlu).[3]