Aline Meunier, stone cutter on the Guedelon project since 01/08/2014, wearing medieval costume, holding a set square and chisel, and standing on a keystone, at the Chateau de Guedelon, a castle built since 1997 using only medieval materials and processes, in Treigny, Yonne, Burgundy, France. The Guedelon project was begun in 1997 by Michel Guyot, owner of the nearby Chateau de Saint-Fargeau, with architect Jacques Moulin. It is an educational and scientific project with the aim of understanding medieval building techniques and the chateau should be completed in the 2020s. Picture by Manuel Cohen