The third day of the 4th International Congress on Construction History included looking at models of roof frames to walking through actual beams and trusses above one of the most visited museums in the world. In fact, today's conference activities included the very exclusive exploration of the wooden roof frames of the stuccoed vault of the Apollo Gallery - breathtaking! After that, we reached the top of the triumphal Arch of the Carrousel through narrow stone stairs hidden in the structure, from there we had a privileged view of the Louvre.