Mashhad is the capital of "Khorasan Razavi" province, located 850 kilometers north East of Tehran, with over 2.42 million people. It is the virtual and spiritual capital of Iran, annually receiving more than 25 million pilgrims to the holly shrine of the 8th Imam (divine religious leader in Islam) from all over the country as well as the world especially from the neighboring countries. Mashhad is the sister city of Dushanbe (Tajikistan), Kuala Lumpur and Kuching (Malaysia), Lahore (Pakistan) and Urumqi (China) and has strong economic cooperation with these cities. Mashhad has joined Metropolis in 2005 and it was selected to be the regional office for the Metropolis Women International Network in 2006; and the second regional branch of Metropolis Training Institute in 2008. Mashhad is home to one of the oldest libraries of the Middle-East called the Central Library of Astan-e Quds Razavi with a history of over six centuries. Mashhad is the major trade centre of Saffron, the most expensive spice in the world, in IRAN. The city benefits from the proximity of the mountains, having cool winters, pleasant springs, mild summers, and beautiful autumns.