Cydathenaeum or Kydathenaion (Greek, Modern (1453-);: Κυδαθήναιον) was one of the demes in ancient Athens. It belonged in the phyle (tribe) Pandionis.
When Cleisthenes formally established the deme system in 508/7 BC, Kydathenaion was the third largest deme after Acharnae and Aphidna.[1] Its population is estimated to have been around 3,300–3,600 people.[2] Kydathenaion was one of the five demes located within the walls of the city of Athens (alongside Koile, Kollytos, Melite, and Skambonidai).[3] It was in the very heart of Athens containing the Acropolis,[4] and possibly the Areopagus.[5]
Notable people from the deme include: