Basilica that was built by Byzantine Emperor Justinian for the name of St. John in 6th Century AD is located on Ayasuluk hill.
There was a small Monastery chapel built in the Late 4th century or Early 5th Century AD.
Ayasuluk Hill was one of the former settlements of Ephesus, and it has been inhabited by some of the early Christian communities of Ephesus that must have built this early monastery and the Chapel in the memory of St. John the Evangelist.
In its time it was the 7th largest Cathedral in the World.
The Church was an important Pilgrimage Spot starting from 7th Century AD.
Many European pilgrims paid a visit to Ephesus and Basilica of St. John along their route to Jerusalem.
The Basilica was built by structural pieces obtained from Ephesus Ancient City and the Temple of Artemis, hence it gives researchers a great source of study.
For instance the Customs' Law of Ephesus inscribed on a 20 feet marble slab was found here in Basilica of St. John used as a building element. Today this Marble Piece is in an exhibit at Ephesus Archaeology Museum.
The remains that are seen today are