The union house opens its doors on the occasion of the Heritage Days! Seat of the miners' union of Pas-de-Calais, then from the Liberation of the regional union of miners' unions CGT, the union house is for nearly a century at the heart of the struggles of the mining corporation. Inscribed as a Historic Monument in 1996, the building has also been part of the 353 components of the Mining Basin property inscribed on the World Heritage List since 2012 (plaque affixed outside 2020).