The sillar stone
The sillar or ignimbrite rock is the symbol of the White City. This rock is the result of millions of years
of volcanic activity in the area, and gases condensed at high temperatures, which are then settled in
large blocks, compose it. It is also known as pyroclastic flow or volcanic tuff, and geologist Clarence Fenner
first described it in 1948. Jose Luis Bustamente y Rivero referred to the sillar as: "the symbol of collective
psychology; toughness and ductility. A fire amalgam where the breath of the volcano melts and brings
rocks and souls to life".
In the prehispanic Arequipa sillar was used only in isolated cases in some homes without importance..
However, since the 16th Century, Spanish builders began using this rock to build vaults and then entire
buildings. In fact, the first person to use sillar in a construction was Nicolas Alonso when he built the Temple
of San Agustin.
After the earthquake that hit the city on the 20th of October 1687, the use of sillar spread, and building
techniques, particularly for houses, were perfected. This promoted the exploitation of many quarries close
to the city such as Añashuayco, Las Cantarillas, La Grande, Paqcha, Señor de la Caña and Ciudad de Dios,
as well as the well-known quarries of Yura.