I could see that this lone rail line was still active by the shiny upper surface of the rails. But I didn't know how active until about three minutes after I took this photo, when a small train appeared from behind and charged into this narrow tunnel. The tunnel has an interesting horse-shoe shape that I've seen in other tunnels in Tottori. I like it; attractively shaped, distinctive and possibly more structurally sound that the usual flat-sided variety.