Samarra is a historic Iraqi city located on the eastern bank of the Tigris River in the province of Salah al-Din , 125 km north of Baghdad , bordered to the north by the city of Tikrit , to the west of Ramadi , and to the east of Baquba , is one of the most important Shiite cities in Iraq because of the shrine of Imam Ali According to the Ministry of Planning in 2013, the population of the city center is over 190,000. In 2007, UNESCO added Samarra to the World Heritage List . [