Al-Mustansiriya School

Baghdad was once the biggest city on Earth and the capital of knowledge. Scholars there translated books from Greek, Persian and Indian into Arabic, and the world learned from them.

In 1233 CE, on the bank of the Tigris river, the caliph al-Mustansir opened a school like nothing before it: free food, free housing, a hospital, a library with tens of thousands of books, and teachers for all four schools of Islamic law under one roof.

In its courtyard there was a famous water clock that told the time of prayer, with little metal figures that moved when the hour arrived. Students walking past would look up to see what time it was.

Students came from Persia, Anatolia, India and Africa. They studied Qur'an, hadith, maths, medicine and astronomy for years, all paid for by charity endowments called waqf.

The brick building still stands beside the river today, with beautiful carved patterns above every arch — a reminder that Muslims built free universities centuries ago.