Ictinus (/ɪkˈtaɪnəs/; Greek: Ἰκτῖνος, Iktinos) was an architect active in the mid 5th century BC. Ancient sources identify Ictinus and Callicrates as co-architects of the Parthenon.Pausanias identifies Ictinus as architect of the Temple of Apollo at Bassae. That temple was Doric on the exterior, Ionic on the interior, and incorporated a Corinthian column, the earliest known, at the center rear of the cella.