The Temple of Apollo Epicurius at Bassai was built in the second half of the Vth century BC (420-410 BC;) by Iktinos, the architect of the Parthenon.
See:
- Robin Hägg (ed.), Peloponnesian Sanctuaries and Cults. Proceedings of the Ninth International Symposium at the Swedish Institute at Athens, 11-13 June 1994. Acta Instituti Atheniensis Regni Sueciae, Series 4, 48. Stockholm: Svenska Institutet i Athen (distributed by Paul Aströms Förlag, Jonsered), 2002. pp. 231; figs. 221 - http://bmcr.brynmawr.edu/2004/2004-04-30.html