Mosul is a city located in northern Iraq on the banks of the Tigris River. It has a population of around 1.8 million people and is the second largest city in Iraq. Samarra is an ancient city located in central Iraq on the east bank of the Tigris River. It is known for its archaeological sites, including the Great Mosque of Samarra, which is one of the oldest mosques in the world. BAGHDAD is the capital of Iraq and is located on the Tigris River in the center of the country. It is the largest city in Iraq with a population of over 8 million people.