This tunnel lies on stage 5 of the Maclehose trail, between the three-way Shatin Pass Road / Jat's Incline / Fei Ngo Shan Rd junction, and Tate's Ridge. Not far from the road I remember seeing a collapsed tunnel entrance, and a noticeboard describing Japanese tunnels.
I'll get photos and a better description of the location next time I'm out hiking that way.
