Mashhad (Persian: مشهد, literally the place of martyrdom) is one of the largest cities in Iran and one of the holiest cities in the Shia world. It is located kilometres ( mi) east of Tehran, at the center of the Razavi Khorasan Province close to the borders of Afghanistan and Turkmenistan. Its population was 2,427,316 at the 2006 population census. Now Mashhad is notably known as the resting place of the Imam Reza. A shrine was later built there to commemorate the Imam, which in turn gave rise to increasing demographic development.