The Bam Citadel, established in the Sassanian period, is situated atop an artificial hill in the northwest quadrant of the old city of Bam and southeast of Kerman. This artificial hill, originally created from debris, elevates the citadel approximately 5 meters above the surrounding urban fabric. It is sandwiched between the mountain range of Kaboodi and Barez and is surrounded by a manmade moat. The Bam citadel is the largest adobe building in the world, located in Bam, a city in the Kerman province of southeastern Iran and is listed by UNESCO as part of the World Heritage Site.This enormous citadel on the Silk Road was built before 500 BC and remained in use until 1850 AD. It is not known for certain why it was then abandoned. The entire building was a large fortress in whose heart the citadel itself was located, but because of the impressive look of the citadel, which forms the highest point, the entire fortress is named the Bam Citadel. The actual citadel is situated in the center of the fortress-city, on the point with widest view for security.The area of the Bam Citadel is approximately 20,000 square meters, and it is surrounded by walls 6-7 meters high. The citadel features two of the "stay-awake towers" for which Bam is famed - there are as many as 38 such towers scattered across the ancient city of Bam. People left the citadel during the 19th century, but the army kept a presence until 1932.