Round City of Baghdad

The Round City of Baghdad is the original core of the city of Baghdad, built by the Abbasid Caliph al-Mansur between 762 and 766 AD as the official residence of the Abbasid court, and known in its own time as the City of Peace. It had a distinctive circular design roughly one kilometer in radius, with four gates named for Kufa, Damascus, Khorasan and Basra, and a central palace and mosque. The renowned House of Wisdom library was later located within its grounds.