The Arg-é Bam
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 listed by UNESCO as part of the World Heritage Site "Bam and its Cultural Landscape". 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.