The temple of Panagia Ekatontapiliani is the most important religious monument of the island and one of the most significant paleochristianic monuments in Greece. It was built in the beginnings of the 4th century AC.
According to the tradition, as Helen was heading to the Holy Land, stopped in Paros due to the rough sea. There, she prayed in a small church and promised Panagia to build in that place a bigger church as soon as the purpose of her trip was fulfilled. (that was to find the Holy Cross).
As for the fulfillment of the oblation there are two options. The one says that Helen herself built the church, while the other and most powerful says that her son Constantine, the first emperor of Byzantium, built it after his mother's death, to fulfill her oblation.
The temple is dedicated to the dormation of Theotokos. The initial building was a three declinable basilic church. Later the emperor Ioustinianos (527-565) changed its shape and since then stays the same.
The name Ekatontapiliani that the church is known appeared for the first time in 1586 in a document of the then Patriarch of Constantinople, Theoliptos the 2nd. The residents of the island connected the church of Ekatontapiliani with Saint Sofia of Constantinople because it was as splendid as that of Saint Sofia with the 100 portals. There's a local legend that says that the church has 100 portals. The name Katapoloani that is also used by the locals is related to the location that the church is built, from the side of the town. This term is found in a document of the duke of Archipelago, Ioanni, dated in the middle of the 16th century.

THE ARCHITECTURE OF THE TEMPLE
The really impressive and monumental temple, dedicated to the Dormation of Theotokos, is a complex of buildings. Apart from the main temple there are five smaller churches (Saint Nicholas, Saints Anargiri, Saint Philips, Saint Theodosia, Saint Demetrios and Saint Theoktisti), the yard with the cells and the Baptistery, the most ancient and best preserved in the entire orthodox east. It has a marble baptizing tub in the shape of a cross where Christians were baptized.
The icon of Panagia holding the Holy Infant is inside the main temple. It is silvered, gilded and decorated with precious stones and pearls. The faces of Panagia and Christ are pictured.
Around the icon is a decoration with 33 smaller pictures, silvered too. In the four corners are the icons of the four evangelists: Matheson, Ioannis, Marcus, Lukas. On the bottom there is a small icon of Zoodohos Pigi dedicated from the archon of Moldovlahia and his family, dated in 1788.

THE BYZANTINE MUSEUM OF THE TEMPLE
There's a Byzantine museum inside the temple. You will see rare ecclesiastic heirlooms and remarkable byzantium icons. Among them distinguish the icons of Saint George, dated from the 15th century and Saint John Prodromo dated from the 16th century. A silver agraffe and silver glass for Eucharist of byzantine times, are some of the exhibits that draw the visitor's attention.