Bam fortress, the world's largest adobe structure, dating to at least 500 BC, located in southeastern Iran. This World Heritage Site is an enormous citadel on the Silk Road. In December 2003, the citadel was almost completely destroyed by an earthquake, along with much of the rest of Bam and its environs but rebuilding started in the same year. This photo is made few months before the earthquake. Bam Citadel is approximately 180,000 square meters, and it is surrounded by gigantic walls 6-7 meters high and 1815 meters long.