Southeast of Gölbaşı is the Dergah mosque complex, Urfa's major pilgrimage destination. From the gate, you enter the colonnaded courtyard in front of the Mevlid-i Halil Cave, which local tradition states is the birthplace of the Prophet Abraham (revered by all three major monotheistic faiths).
The western side of the complex is dominated by the honey-toned, Ottoman-style stone bulk of the Mevlid-i Halil Cami. The airy, domed interior contains some lovely tile details and arabesque medallion designs.
According to local lore, the Prophet Abraham's mother hid in the Mevlid-i Halil Cave when pregnant to escape the wrath of King Nimrod who, responding to a prophecy that proclaimed a child soon to be born would destroy his kingdom, had ordered all newborns killed. It's said that Abraham lived here hidden until he was 15 years old. There are separate entrances into the cave for men and women. Women should don a headscarf before entering and everyone should be modestly dressed. Inside pilgrims pray in the cave-cut room.