The most remarkable sight on Sikinos, Episkopi sits on a ridge above the western side of the island, reached by a one-hour walk on a well-marked path from the Hora. What looks from a distance like a small Byzantine chapel turns out to be something much older: a Roman funerary monument from around the 3rd century AD, its carved pilasters and classical proportions still visible beneath centuries of ecclesiastical additions.
The path up from the Hora is itself worth the walk — it follows old mule tracks through terraced fields and dry-stone walls, with the sea visible on both sides of the island as you gain height. The monastery buildings around the church are now mostly ruined, but the church itself is intact and occasionally open. Allow two hours for the round trip, bring water, and time it for morning or late afternoon in summer.