The sanctuary dedicated to the deities of Apollo, Demeter and Kore was built around 530 BC.
Sources:
- Vassilis K. Lamprinoudakis, The Ancient Sanctuary of Apollo and Demeter at Gyroulas, Sagri - http://www.naxos.gr/en/naxos/sights-and-sightseeing/archaeological-sites/article/?aid=1257
- https://en.wikipedia.org/wiki/Temple_of_Sangri