Renaze, 90 m west of Angers, was an important centre for the mining and quarrying of slate from the 15th century until the last workings ceased in 1975. The museum was established around the headstock of the former Longchamps mine by the Perrayeurs Mayennais, the association of stone cutters. A massive electric motor of 1904 that powered winding apparatus and air compressors remains in place. The museum holds a particularly notable collection of tools. Displays show the methods used in mines and quarries to dislodge large blocks of slate weighing up to 500 tons. A narrow gauge railway takes visitors on tours through former workings, which are of great interests to ecologists and geologists as well as to those concerned with industrial heritage.