The chest of the four keys Curiosity · Yanguas, Tierras Altas, Soria Image of Yanguas, not of the place itself. The church of San Lorenzo, of late Gothic, guarded the chest of the municipal archive closed with four different locks: each key was in the hands of a different mayor and the chest was only opened with all of them present. Photo: Pigmentoazul (CC BY-SA 3.0) What to see and do in Yanguas