Harran lies on the southern border of Turkey, under 20 miles from Syria. Here stood as a strategic location for thousands of years as the crossroads of Mesopotamia and Persia. In the center of town lies the Harran Castle, built on the site of much earlier ruins of unknown origins. Even though much of the present walls date to the 13th century, the castle itself is believed to be constructed during the Roman-Byzantine period. The great mosque excavated nearby was found to be the oldest in all of Anatolia, built between 744-750. Likewise, the first Islamic university in the world is also found in this small, but historically important town. These ruins are testament to the prominence Harran had, as both a center of learning and a crossroads of faiths, as was also known as the hometown of Abraham.