Timbuktu's greatest treasure is not its mosques but its manuscripts. Between the thirteenth and seventeenth centuries, the city accumulated more than 700,000 handwritten documents — treatises on astronomy, mathematics, medicine, law, history, and theology, written in Arabic by scholars from across the Islamic world and by Timbuktu's own intellectual class.
The Ahmed Baba Institute of Higher Learning and Islamic Research (known as IHERIAB) houses the largest institutional collection, with more than 100,000 manuscripts now stored and being digitised. Private family libraries in the city hold many more — some families have manuscripts that have been in their possession for 500 years. Viewing arrangements can sometimes be made through the institute or through local guides. The museum near the Sidi Yahya Mosque has a good selection of illuminated manuscripts on display.