Mosul, Iraq is known for its several old churches, some of which originally date back to the early centuries of Christianity.
The ancient churches of the city are often hidden through labyrinthine alleyways behind thick walls and are therefore not easy to find.
The oldest church in Mosul, Shamoun Al-Safa (St. Peter), dates from the 9th century and is very difficult to find.
It has a deep underground courtyard and a cemetery between high walls containing some ornate tombstones of Maslawi merchants.
The exact time of its foundation is unknown, but it can be assumed that the Syriac Orthodox Church of Saint Thomas dates prior to 770, since reference tell that Al-Mahdi, the Abbasid Caliph, listened to a grievance concerning this church on his trip to Mosul.
Al-Tahira Church dates back to the 7th century, and it lies 3m below street level.
Mar Hudeni is an old church of the Tikritans in Mosul, dating back to the 10th century.
Pilgrims from different parts of the north visit it annually in spring, when many people travel to its surrounding areas on holiday.
The only monuments left are a marble door-frame decorated with a carved Estrangelo (Syriac) inscription and two niches which date back to the 13th or 14th century.
It was built by Mar Matte, a monk who fled with several other monks in 362 from the Monastery of Zuknin near the city of Amid (Diyarbakır) in the southern part of Asia Minor (present-day Turkey) and the north of Iraq during the reign of Emperor Julian the Apostate (361-363).