Centre des archives du monde du travail de Roubaix, National labor archives in Roubaix, France.

The Motte-Bossut factory is a red-brick cotton spinning mill over one hundred metres long, built in the neo-Gothic style between 1866 and 1891. Two hexagonal crenellated towers flank the main entrance, one of them serving as a chimney, and a tall square brick chimney rises on the right. About 300 windows light its five floors, and since 1993 it has housed the Archives nationales du monde du travail.

Louis Motte-Bossut founded the spinning company in 1843 and built a cotton mill on a canal branch, partly destroyed by fire in 1845 and rebuilt with 44,000 spindles. A second fire in 1866 destroyed it completely; production moved to a fireproof annex built in 1862, which became today's building. Two towers marking the entrance were added in 1889 and 1891, and the mill closed in 1982.

The building's nickname, "la filature monstre", came from its output exceeding that of all other mills in Roubaix and Tourcoing combined. The two crenellated towers were added to mark the factory entrance, the western one in 1889 and the eastern one in 1891. The archives now keep records of firms, trade unions and employers' organisations.

The reading room of the Archives nationales du monde du travail sits in the former Motte-Bossut spinning mill at 78 boulevard du Général Leclerc. Access is aimed at researchers, who should contact the archive in advance and bring identification. The brick facade, towers and chimney can be seen from the boulevard without entering.

The two entrance towers were built separately: the west tower in 1889, the east tower in 1891. One of them also served as a chimney. The building is over 100 metres long, five storeys high and has around 300 windows.