800-Year-Old Iron Reinforcements Discovered During Notre-Dame Repair.
Iron reinforcements were found in the mid-12th century construction of Notre-Dame Cathedral during restoration work after the 2019 fire. The discovery changes how researchers thought the church was built and provides insights on the iron trade in 12th-century Paris. The iron staples were inserted at load-bearing points, improving the cathedral's structural integrity and making it possible to build its slender gothic architecture. The discovery was unexpected and indicates that Notre-Dame set the stage for what came after in medieval French cathedrals. The restoration work has opened up opportunities to study aspects of the church's construction that were previously impossible to analyze.