The current coordinates point to the northern “atoll” of Lake Bardawil which is very unlikely to have been anything close to an inhabited location (for obvious reasons), let alone a bishopric. “El-Katieh”, “El-Kas” and “Mahemdiah” also didn't return nothing from any map known to me. Bir Qatia (30°57′17″N 32°44′21″E / 30.9546501°N 32.7391151°E / 30.9546501; 32.7391151), though, seems to be the location, given the similarity between Greek Kassion and Arabic Katieh. ―Eduardogobi (talk) 04:26, 3 September 2021 (UTC)Reply
