The church of Virgin Mary was located close to the Harbor Baths of the ancient city of Ephesus. It was a 260 m long basilica which was used initially as a medical centre and a small chapel was added to it in the 10th century AD. It could be accessed through an atrium which had been paved with marble slabs. Crosses and metal rosettes adorned its walls and a baptisma pool had been constructed to the north of the church. A great part of the walls and the pillars have survived nowadays.
The Council of Ephesus held meetings there in 431 AD discussing the role of Saint Mary as the Mother of the God. They agreed at least on the fact that she came to Ephesus accompanied by Saint John and that she died there.
This is a very important church for Christianity because it was the first one devoted to the Virgin Mary. The Council of Ephesus and the Synod declared that church as the centre of Christianity in 449 AD.
According to recent excavations, the church was built on the south stoa of the Temple of Hadrian Olympios and its foundations can be seen even today.