Every mining company in the north of France needed an office, and the one that held the pay books, maps and plans of the Lens pits needed a large one. The Grands Bureaux of the Société des Mines de Lens stand in the middle of the town as a monument to an organisation that employed tens of thousands of men and controlled whole districts: the housing, the schools, the shops, the churches and the clinics were all in the company's gift. The building was part of the reconstruction after the First World War, when the town had been reduced to rubble and the company set about rebuilding its pits and its headquarters in brick and stone.
It is a handsome, solid building, designed to impress, and it is a good place to think about how the mining basin worked. The company paid wages and ran the cités, the ordered streets of miners' houses with their gardens and washing lines. The Société des Mines de Lens was founded in the middle of the nineteenth century and ran until the French coal industry was nationalised in 1946. The last pit in the basin closed in 1990.
Riding in and around Lens is easy but unremarkable. The streets are flat and straight, with a good deal of cobbled paving and tram-like patches of rough tarmac, and the traffic is thick at rush hour. The town is a busy one, with thirty-eight thousand residents, and fuel stations are everywhere. For a coffee, find a brasserie near the station. For something more filling, a plate of potjevleesch, a cold terrine of mixed meats, is a Flemish speciality that has crossed the border into Artois.
If you have time, climb the slag heaps at Loos-en-Gohelle for a view that explains the landscape better than any museum. The twin cones are the highest in Europe, and on a clear day the whole plain is spread out below.
The weather in the north is changeable, with rain at any season. The best days are in late spring and early autumn, when the light is soft and the brick glows. Winter is raw, grey and damp.