The Modernista Vapor Aymerich, Amat i Jover woollen mill is one of the finest examples of industrial Modernista architecture in Catalonia. Designed by the architect Lluís Muncunill and opened in 1908, it is currently the headquarters of the Museu Nacional de la Ciència i la Tècnica de Catalunya - MNACTEC (National Museum of Science and Technology of Catalonia).

With its characteristic roof of Catalan-vaulted skylights supported by cast iron pillars, and a 42-metre high chimney, the building housed the entire process for transforming wool, from fleece to woven cloth. The name by which the mill is popularly known, 'El Vapor' (steam), refers to the steam engine that was its driving force until 1914.

The museum today reflects the building's industrial past as a woollen mill. The aim of the MNACTEC is both to conserve and raise awareness about Catalonia's scientific, technical and industrial heritage, while also demonstrating the social impact it had. The permanent exhibitions encompass the textile industry, sources of energy, computing, chemistry and transport, amongst others.

The MNACTEC also oversees a Territorial System that coordinates 26 museums and other centres specialising in industrial, scientific and technological heritage. Each of them provides a unique thematic perspective that helps explain the process of industrialisation in Catalonia, as well as the technical, social and cultural repercussions it had.