At the beginning of the 20th century, Eusebi Güell established in Clot del Moro (Castellar de n'Hug) the Compañía General de Cementos y Asfaltos - ASLAND, the first Portland cement factory in Spain. The company became one of the most prosperous and best equipped technically of its time, fact that generated a great influx of workers in that area of the Pyrenees. The factory was built by Rafael Guastavino (1901-1904) and different services were created for the accommodation of the workers but also for the material supply.
The coal for the furnaces of the factory came from a mine in the nearby Catllaràs Massif, so Güell commissioned Gaudí a building for its engineers and professionals. The project consisted in a chalet, the walls of which form a continuous ogive joining façades and roof. The access to the inside is gained by a semicircular staircase, which today is no longer there. The shape of the windows, protruding outside, reminds those of the loft of the Casa Milà. The building, known today as the Catllaràs Chalet, was considerably modified when it became a youth hostel.