Metti Franzen was born in 1927 in Rumelange, Grand Duchy of Luxembourg. Former iron miner in the galleries of the Walert mine, he is one of the last witnesses of underground mining work in the Grand Duchy. The Walert Mine ceased operations on 31 December 1963 and was converted into a museum in 1973. Metti Franzen contributed, along with others, to the foundation of what is now the National Museum of Iron Mines. He was then and for more than thirty years an attentive and passionate guide of the MNM.