A mineshaft is a deep, narrow hole that goes down from the ground into a mine. Think of a well, but for people, air, and rock, not for water. Workers ride cages or lifts up and down it. From the bottom, tunnels then run out to the places where the coal or metal is. The shaft is the up-and-down part; the tunnels are the sideways parts. In careful talk, shaft means that vertical passage. People do sometimes say shaft more loosely for other mine holes, but the tidy picture is the deep narrow way down.