The Citadel of Bam: The World’s Largest Mud Building

Sometime between 579 and 323 BC during the Achaemenid Persian period, the Citadel of Bam (in Persian Arg-é Bam) was built in southeastern present-day Iran, a huge fortress made of clay that is considered to be the largest adobe building.

It is located next to the city of the same name in the province of Kerman and near the border with Pakistan, and consists of a large fort that contains an inner citadel (although today the entire complex is called a citadel).

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The original Achaemenid nucleus was expanded by the Parthians and the Sassanids, who between 224 and 637 AD built new fortifications and walls. The Arabs conquered it in 645 and from the 10th century on, the name of Bam began to appear in Islamic sources, which speak of its impregnable fortress and its busy bazaars.

The fortress remained inhabited without interruption until the construction of the new city of Bam began in 1900, and its inhabitants gradually moved to the new city. The citadel remained as a military garrison until 1932, when it was definitively abandoned.

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The complex occupies an area of 180,000 square meters, surrounded by huge and imposing walls up to 7 meters high that form a perimeter of 1,815 meters in length. Behind the iconic entrance of the fortress, flanked by towers, there are some 400 houses and other public buildings and bazaars that surround the central, higher area, in which the citadel itself stands with the barracks and the Palace of the Four Seasons. .

Among the most characteristic and famous elements of the place are the 67 observation towers distributed throughout the complex, two of them in the citadel. All the buildings are constructed with an ancient technique that uses layers of mud (chineh), sun-dried mud bricks (khesht) and domed vaulted structures, giving the complex the appearance of a huge sand castle.

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The fortress, which only has one entrance gate, had the capacity to survive long sieges, as it had water wells, underground irrigation channels, gardens and fields for cultivation and domestic livestock. Hence its reputation for impregnability. The buildings also had wind towers , structures of various sizes that allowed the air to be redirected towards the interior, and even filtered by passing it through ponds, to cool it and eliminate dust.

On December 26, 2003, an earthquake destroyed practically 70 percent of the structures in Bam, their epicenter being located about 7 kilometers below the citadel. With a 6.6 on the Richter scale and more than 20,000 dead, it was one of the worst suffered by Iran. Interestingly, the structures of the citadel that had been modified and extended repeatedly over time were more damaged than the old structures that had never been reformed.

The reconstruction of the citadel of Bam began the following year, applying anti-seismic construction standards, and with the collaboration of several countries such as Japan, Italy and France. For this reason, most of the structures that we can see today are modern, although they almost exactly reproduce the old citadel.