Underground old ore gold mine tunnel shaft passage mining technology with timbering
Palabras clave
mine,
shaft,
geology,
mining,
heavy,
deposit,
rock,
stone,
tunnel,
gallery,
passage,
ore,
abandoned,
dark,
gold,
iron,
mineral,
industry,
wood,
quarry,
timbering,
cavern,
cave,
timber,
wagon
){kind=link}