The Šaleška Valley, eight kilometres long and two kilometres wide revealed its secret, God knows for how long concealed, in the middle of the 18th century, when Reverend Steiz sent a written report about a coal deposit in the valley.

Franz Mages, above all an active explorer of the mining industry, and the noble Daniel Lapp, founder and owner of the Velenje mine, dedicated their work to this area from around 1870 to 1914.