The location for the Guédelon medieval construction site was chosen according to its proximity to raw materials like water, forests, and a quarry. The stones are extracted from a quarry located at the foot of the castle. They mostly consist of hard ferruginous sandstone that often breaks the stonemasons' tools. One day, a stonemason wore out 24 broaches on his stones, and the site's blacksmith spent his day redoing them. As oak is also a particularly hard wood, the lumberjack's master saw often needs repair.