Samarra, which is located on the banks of the Tigris River, is one of the four Islamic Holy Cities of Iraq. Once the capital of the Abbasid Caliphate, which stretched from Tunisia to Central Asia, the ancient city of Samarra has maintained its original city plan and contains traces of remarkably preserved architecture. The Great Mosque of Samarra, with its 52-m high spiraling minaret- the Malwiya tower, was designed to fit 80,000 worshipers and was once the largest mosque in the world. Sadly, the gold-domed Al-Askareyya Mosque, which contained the tombs of two ninth century imams, was destroyed during a bombing in 2007. Because of violence and hostilities, Samarra was placed on the endangered places list in 2007. Samarra is a fascinating archaeological site, much of which is left to be excavated, and a lasting testament to the wonders of the ancient Muslim world.