Switzerland. Canton Ticino. Lugano. Three boys walk up the stairs. They all come back from school and carry small backpacks. On the wall (R) of the infant school, a banner with a drawing explaining dry stone construction in the context of stone walls. Dry stone, sometimes called drystack, is a building method by which structures are constructed from stones without any mortar to bind them together. Dry stone structures are stable because of their construction method, which is characterized by the presence of a load-bearing façade of carefully selected interlocking stones. Dry stone construction is best known in the context of stone walls, traditionally used for the boundaries of fields and churchyards, or as retaining walls for terracing, but dry stone sculptures, buildings, bridges, and other structures also exist. The art of dry stone walling was inscribed in 2018 on the UNESCO representative list of the intangible cultural heritage of humanity. 15.09.2020 © 2020 Didier Ruef