The Notre-Dame de Paris is the first known cathedral of Gothic-style architecture to be initially constructed with extensive use of iron to bind stones together. The 2019 fire that significantly damaged the cathedral enabled analyses leading to this discovery, by Maxime L’Héritier of Université Paris 8, France and colleagues, who present these findings in PLOS ONE on March 15, 2023.
Click here for original story, Fire reveals Notre-Dame de Paris Cathedral was historical first in using iron reinforcements in the 12th century
Source: Phys.org