The waterfall rights to the Mår watercourse were bought by the State in 1920, but it was the Germans who began construction of the power station in 1941. Because of the events in Rjukan during the Second World War, work stopped. It wasn't until 1948 that the two first machines were put into operation. Today, the power station has five generators in operation. Mår power station can also boast the longest wooden staircase in the world (almost 4000 steps), which you will find inside the mountain.