Dayro d-Mor Gabriel (Classical Syriac: ܕܝܪܐ ܕܡܪܝ ܓܒܪܐܝܠ; The Monastery of St. Gabriel), also known as Deyrulumur, is the oldest surviving Syriac Orthodox monastery in the world. It is located on the Tur Abdin plateau near Midyat in the Mardin Province in southeastern Turkey. It has been involved in a dispute with the Turkish government that threatened its existence.