Athmonum or Athmonon (Ancient Greek: Ἄθμονον), also Athmonia (Ἀθμονία), was a deme of ancient Attica, situated on the site of the Marousi (Amarousion). The name of the modern village has been derived from Amarysia, a surname of Artemis, who was worshipped under this designation at Athmonum. An inscription found near Marousi, in which the temenos of this goddess is mentioned, puts the matter beyond dispute.