By the Classical period, the races were run by ephebes also in honour of Hephaestus and Athena. Prometheus' association with fire is the key to his religious significance and to the alignment with Athena and Hephaestus that was specific to Athens and its "unique degree of cultic emphasis" on honouring technology. The festival of Prometheus was the Prometheia. The wreaths worn symbolised the chains of Prometheus. There is a pattern of resemblances between Hephaistos and Prometheus. Although the classical tradition is that Hephaistos split Zeus's head to allow Athene's birth, that story has also been told of Prometheus. A variant tradition makes Prometheus the son of Hera like Hephaistos. Ancient artists depict Prometheus wearing the pointed cap of an artist or artisan, like Hephaistos, and also the crafty hero Odysseus. The artisan's cap was also depicted as worn by the Cabeiri, supernatural craftsmen associated with a mystery cult known in Athens in classical times, and who were associated with both Hephaistos and Prometheus. Kerényi suggests that Hephaistos may in fact be the "successor" of Prometheus, despite Hephaistos being himself of archaic origin.