The River Orontes (Asi in Turkish) divides Antioch in two. In the old town you will find the Habib Neccar Cami, a mosque on Kurtuluş Caddesi, just south of St. Peter's. It's popularly dated from the 7th century and called Turkey's oldest mosque. More likely, a church of John the Baptist originally stood here, replacing a temple, and this was converted to a mosque, converted back to a church by the crusaders, then destroyed in 1268 by the Mamluk Sultan Baybars. He then
had the current building constructed. It has since been much restored. A side chamber contains two sarcophagi, labeled as the prophet Jonah and John the Baptist, while downstairs are the tombs of "Habib-i Neccar," an otherwise unidentified early Christian martyr mentioned in the Koran, and "Sham’un al-Safa" (Simon the Loyal), perhaps the Apostle Simon Peter. All presumably survive from the Byzantine Church, and with that pedigree could even be genuine. Between here and the river is the bazaar quarter, a real change of pace: the feel is more Syrian and Arab than Turkish.
Corner of Kurtuluş and Kemalpaşa Cad., Antakya, 31060, Turkey