all the machines for making tacks that Víctor Sánchez, a local businessman, was installing in the village of Armal with the aim to start a strong tacking industry able to face the great external competition, especially that English one, which finally made unfeasible the traditional means of working iron in the municipality. 20th century The end of the 19th century and the beginning of the 20th were years of important migratory flows, especially to the Americas. From these years date several large houses, property of emigrants who had made fortune in the Americas, such as for example Villa Anita. In addition, the money furnished by many emigrants contributed decisively to the construction of various schools in several villages of the municipality and the elementary school of the capital town, known as "Las Graduadas", in 1934, which was promoted by the "Sociedad de Instrucción Naturales del Concejo de Boal" ("Association for the Education Natives of the Municipality of Boal") in La Habana (Cuba). Also in these years several public washing houses were built in the municipality. Some other infrastructures of capital relevance for Boal were built at the beginning of the 20th century. That was the case of the road connecting Navia and Grandas de Salime, with the construction of the stretch from Navia to Boal. Furthermore, in 1934 it was built the dam of Doiras, and in the year 1951 it was started the large-scale exploitation of the tungsten mines near Penouta, although they closed in 1961. The decadence of tungsten mining, which had employed up to 254 workers, and the end of the construction of the big reservoirs along the Navia River, together with the gradual abandonment of cattle farming (still at present the main economic activity of the municipality) led to new migratory flows, especially from the 1950s on, but in this case they were directed preferentially to other regions of Spain (the industrialized center of Asturias, Madrid, etc.) or to Europe (Germany, France, Belgium, Switzerland, etc.), giving rise to a progressive depopulation that still continues at present. Geography Physical geography Being located in the middle basin of the Navia River, the municipality of Boal is crossed by that river from south/south-east to north-east, where its course acts as a natural border with the neighboring municipality of Villayón. On its way through this municipality, the Navia River is dammed first in Doiras, and later, downstream, by that of