The snow and the ice were highly appreciated because of their preservative properties since the Roman Empire; at that time the first storehouses were devised to be able to use them outside the winter season. In Galicia, these constructions, the neveros, became popular during the Middle Ages and monks, such as the ones in the Cistercian monastery of Santa María da Franqueira, in the municipality of A Cañiza, used these kind of refrigerators.
The Cistercian monks knew well the snow and the ice properties and used them for therapeutic and food preservation purposes. Furthermore, they also knew the possibility of preserving food by keeping them in neveros under suitable temperature conditions. They built at least two refrigerators: the nevero of A Franqueira or Os Frades and the nevero of Petán, and they also used the puddle of the Deva River.
The old neveros have been traditionally linked to Galician medieval monasteries such as the monastery of A Franqueira, whose origin is unknown. The earliest evidence of the existence of this monastery dates back to 1063, when, according to a reference from Father Jerónimo Ávalos and transmitted by Hipólito de Sá, King Fernando I donated the monastery to the abbot and to the monks. The monastery was consolidated in the 14th century. The church, the only element of the monastic complex that is present nowadays, was built around 1343. This date appears on the lintel of the building, bounded to the tympanum, and it is seen on the main façade of the temple. The monastery of A Franqueira was the only monastery in Galicia that was part of the Cistercian Order during the Middle Ages.
The monks looked for suitable places in high points and close to streams in order to build the neveros. They should be situated in accessible places to shorten the time spent on moving the snow and the ice; logically, this action was carried out in the middle of the night taking advantage of the cold temperatures at night and avoiding the heat of the sun. The excavation penetrated the ground until it reached rocks and the structure was covered with straw, tiles or stones. In the bottom of these containers, in most cases circular, canals were opened for the drainage of ice; moreover, the walls of the neveros were covered with plants that were used as thermal insulations. Layers of snow, up to 60 centimetres high (around 24 inches), were piled up and the snow was also crushed until it became ice.
According to the references that have survived to the present day, the ice was piled up and transported after the snowfalls. There is written information and remains of many neveros in Galicia, such as the nevero of A Meda, in Parada de Sil, or the nevero of O Campo do Eirado, in Xunqueira de Espadanedo.
The history of the monastery of A Franqueira came to an end in 1835, when religious people were forced to abandon it because of the ecclesiastical confiscations of Mendizábal. The temple is now a parish church and it welcomes one of the most popular pilgrimages and devotions in Galicia and in Northern Portugal.
The neveros (stone structures used by monks in the past to store ice and snow) located near the old monastery of A Cañiza stored ice for the preservation of food and for therapeutic and cooling purposes