The Basilica of St. John is in Selcuk on Ayosolug Hill, near Ephesus.In the 4th century a small chapel was built over the grave of St. John. The Basilica that is seen today was constructed by Justinian I in the 6th century. It is believed that St. John (Apostle - Disciple of Jesus) spent his last years in the region around Ephesus bringing Mary, the Mother of Jesus with him after the crucifixion. Historically, from earliest Christianity pilgrims have gone to Ayosolug Hill to visit St. John’s grave.
According to Acts, Apostle (St.) Paul during his third evangelizing journey traveled all around the various cities and states presently known as Turkey, including Ephesus, which was an important Christian center. He stayed there for almost three years, Apostle John is believed to be the author of the Fourth Gospel and the book of Revelation found in the New Testament of the Bible. (This and additional epistles by a “John” is open to scholarly debate.) However, the Gospels and scholars seem to agree that the John and his brother James (both apostles of Jesus) were the sons of Zebedee and began to follow Jesus while fishing in the Lake Galilee with their father.