The Monastery of Agios Antonios occupies the summit of the hill of Kephalos, dominating the fertile plains of the east coast of Paros, east of the village of Marpissa or Tsipidos (as the present-day settlement was called up to 1926).
A ruined kastro of the Late Medieval era predates the Monastery of Agios Antonios on the hilltop. The outer fortification wall of the kastro was constructed around 1500 under the authority of the Venetian lord of Paros, Nicolo I Sommaripa. According to archaeological evidence, an earlier fortified settlement existed on the same site already at the beginning of the 13th century, while the Florentine priest Christophoro Buondelmonti testified to its existence when he visited Paros around 1415-1420. This is the site where the last page of the history of Venetian authority on Paros was written. The kastro of Kephalos was besieged and captured in 1537 by Hayreddin Barbarossa, Grand Admiral of the Ottoman fleet. According to local tradition and later historical sources, Barbarossa removed the Venetian authority, captured the whole island and slaughtered 6,000 inhabitants.
The ruins of nine single-aisled churches are to be found within the fortification walls of the kastro. The largest of them, dedicated to the Annunciation, has been recently restored; according to the dedicatory inscription above its doorway, the church was built in 1410, comprising the oldest dated church on the island of Paros.
The history of the Monastery itself between 1597 and 1642 remains largely unknown. Before 1639, the monastic church was a property of Ioannis Poulios, priest of the village of Tsipidos. The Monastery started to operate as such in 1642, when Anthimos Skordilis was appointed as its first abbot. According to a signet of April 1767 by Patriarch Samuel, Hosios Cyrillos Papadopoulos (1748-1833), born in the village of Marpissa and a distinctive figure of the period, was appointed abbot of the Monastery.
Agios Antonios gradually acquired large property and came under the protection of the family of Nicolaos Mavrogennis of Wallachia.
The monastic church, a three-aisled cruciform basilica with two domes, is dedicated to Saint Anthony and comprises a unique architectural masterpiece on the island.
The church preserves traces of wall frescoes of the 16th-18th centuries, a wooden-carved templon-screen of 1693, a marble ambo, a marble altar supported by ionic capitals, a wooden-carved ciborium (1733), and a marble ostensorium of the Venetian period bearing the Sommaripa’s coat-of-arms.
Agios Antonios is one of the most important pilgrimage sites on the island. During the period of its peak (17th-19th centuries), the Monastery was distinguished as a major monastic and charity centre. Its contribution to local economy and culture was of great significance.
The Monastery celebrates three times a year: on the name-days of Agios Antonios (17th January), Prophet Elias (20th July) and Virgin Myrtidiotissa (24th September).