A walk on the island is enough to realise that Sifnos has hundreds -more specifically 237- churches and monasteries. "Witnesses" of the history, the architectural heritage and the religious life of the island, some of them are characterised as historical monuments, due to the great religious and architectural interest they present.
These include the monastery of Panagia Chrissopigi, Panagia Angeloktisti in Katavati, the monastery of Prophitis Helias the Psilos, Panagia Eleoussa in Kastro, Panagia tou Vounou, the monastery of Agios Ioannis Chrissostomos in Kato Petali, etc.
From the churches in Apollonia the ones that stand out include those of Panagia Oyranofora (with gilded iconostasis, impressive belfry and old icons), Agios Sozon (with impressive wooden chancel) and Stavros (built where the Temple of Apollo used to be during the 7th century BC).
In Artemonas visit the church of Agios Konstantinos, built in 1462, Panagia of Ammos and Panagia Kochi and in the village of Kastro the church of Panagia Eleoussa dating back to the 17th century (with precious Epitaph, old icons and wooden chancel), the church of Epta Martiron (built on a rock beneath the village) and the church of Agios Stefanos, where the school of Agios Tafos was housed during the Turkish rule.