Herat is the second largest city in Afghanistan, located in the north western part of Afghanistan. It is famous as Nagin Aseeya or Diamond of Asia in some literature. The city has a rich history of more than 3000 years. Herat dates back to the Avestan times and was also traditionally known for its wine. The city has a number of historic sites, including the Herat Citadel and the Mosallah Complex. During the Middle Ages Herat became one of the important cities of Khorasan, as it was known as the Pearl of Khorasan.