Abstract Cadalso de los Vidrios leucogranite is extracted from the Sierra de Guadarrama (Spanish Central System) under the trade name ‘Blanco Cristal’. It is a fine- to medium-grained, hypidiomorphic and equigranular building stone that has been used in many heritage buildings, such as the Villena Palace (1534). The current annual production of Cadalso de los Vidrios leucogranite is approximately 8000 m 3 , of which 40% is exported around the world. It has been used in places such as the Vieux-Port in Marseille (France), Cork International Airport (Ireland) and the Puri EXIM Bank of Jakarta (Indonesia) among others. It is currently being used in the construction of the iconic tower of Jesus Christ of the Sagrada Familia Basilica, in Barcelona (Spain). Cadalso de los Vidrios leucogranite Blanco Cristal has excellent petrophysical properties, a uniform colour and good resistance to thermal shock and freezing temperatures. These qualities make Blanco Cristal an ideal material for monuments and buildings.

Abstract The knowledge that societies have of their geological environment and of the materials used in their heritage is of great importance for the sustainable use and conservation of traditional natural stone architecture. Similar weathering mechanisms occur in natural environments and the built environment and, in both cases, weathering may endanger both natural and built heritage. The Sierra de Guadarrama (Spanish Central System) is a privileged area in which natural and built heritage coexist. This paper describes an area of particular monumental and geological interest on the northern slopes of the Sierra de Guadarrama; its main aim is to propose an itinerary for members of the public, presented as a route through the area around Segovia, in which architecture/cultural heritage and an Earth sciences approach are brought together with an educational purpose. To this end, some connections are established between weathering forms in natural and built environments, as well as between the lithological characteristics of the rocks used in construction of ancient monuments in the area and the distribution of stresses and loads of walls.