The Arg-é Bam (ارگ بم in Persian, "Bam citadel") was the largest adobe building in the world, located in Bam, a city in the Kerman province of southeastern Iran. It is recorded by Unesco as a World Heritage Site. This enormous citadel, situated on the famous Silk Road, was built some time before 500 BC and remained in use until 1850 AD. It is not known for certain why it was then abandoned.