Answer: Baghdad

During the late 8th century and early 9th century, Baghdad was the intellectual capital of the Islamic empire that dominated the region. Librarians and scholars there worked to amass an enormous library of volumes from both inside and outside the empire. The demand for books was so high, in fact, that it was difficult to keep up with the desire for new tomes. The Caliph of Baghdad rewarded scholars who translated foreign tomes into Arabic handsomely.

How handsomely? They were given the weight of the book in gold as compensation for their contributions to the city’s massive library. As a result of the hefty bounty put on books and the extensive translations completed by Islamic scholars, thousands of Greek, Roman, Persian, and Indian works were preserved and archived.