Turkey. Selcuk. General view of the 6th century Byzantine citadel fortress and the Basilica of St John on Ayasuluk hill. The Basilica of St John was built by the Emperor Justinian in the 6th century AD on the site of earlier shrine dating from the 300’s. The Basilica is 110 metres long and 40 metres wide and was once crowned with one large dome and ten smaller ones held up by columns of which some have been re-erected. The tomb of St John the Evangelist is believed to be located under the main central dome.