Fez was the capital city of modern Morocco until 1925 and is now the capital of the Fès-Meknès administrative region. The city has two old medina quarters, the larger of which is Fes el Bali. It is listed as a World Heritage Site and is believed to be one of the world's largest urban pedestrian zones (car-free areas). University of Al Quaraouiyine, founded in 859, is the oldest continuously functioning madrasa in the world. The city has been called the "Mecca of the West" and the "Athens of Africa". The city was founded on a bank of the Jawhar river by Idris I in 789, founder of the Zaydi Shi'i Idrisid dynasty. His son, Idris II (808), built a settlement on the opposing river bank. These settlements would soon develop into two walled and largely autonomous sites, often in conflict with one another: Madinat Fas and Al-'Aliya. In 808 Al-'Aliya replaced Walili as the capital of the Idrisids. Located by the Atlas Mountains, Fez has a Mediterranean climate with cold and rain in the winter and dry hot days in the summer months between June and September.