The leaflet one gets at the St. John basilica indicates this is a cistern that was constructed during the Turkish period from what formerly had been the apse of a basilica. The central section had a column and two arches added for support. The inside was coated with a strong red mortar. It is on a rocky platform, at the peak of the hill. The leaflet also informs us it is believed St. John used to sit on that platform while writing his [part of the] Bible and prayed here too, when he was an old man, aged ninety.