The UNESCO World Heritage-listed Sixty Dome Mosque in Bagerhat, Bangladesh, is deteriorating rapidly due to rising salinity and the impacts of climate change. Cracks, peeling lime plaster, and salt deposits are visible on the mosque’s walls, domes, and especially the mihrab. Studies by Khulna University, the National Geographic Society, and ICOMOS reveal that temperature rise, industrial pollution, monsoon humidity, and groundwater salinity are accelerating the damage. The Department of Archaeology has formed a five-member expert committee led by former Director General Dr. Md. Shafiqul Alam to assess the structure, which found the mihrab at risk of collapse. Corrosion in iron clamps has weakened the building’s load-bearing capacity. Regional Director Lovely Yasmin stated that with UNESCO’s assistance, a detailed decay map will be created, and international experts will join urgent conservation efforts. Experts warn that without immediate action, the mosque could be declared an ‘endangered world heritage site,’ posing a significant cultural loss for Bangladesh.