Pok Fu Lam Reservoir Road (Peak) Sentry box? [c.1938- ]

Was going down from the peak on Pok Fu Lam Reservoir Road and right around Jardines Corner (5 mins down from the peak) was a structure that I assume to be a sentry box. It has a small loophole facing the road uphill (forgot to look for any on the other side) and a clear (sealed) doorframe. It looks very similar to the machine gun 'box' on Wong Nai Chung gap, part of the West Brigade HQ complex ( http://gwulo.com/node/32356 ). 

I could imagine this being an intermittent sentry point between the Batteries of the Peak and Pok Fu Lam Reservoir encampments   (primarily the Forward Dressing Station noted by Dr Solomon Bard that   T & David  were talking about. I imagine casualties would have gone past this point from Batteries on the Peak to the Forward Dressing Stations?   ).

I think there could have also been a roadblock here during war time. Like one of those (British sentry roadblocks )  mentioned in A. H. Pott's wartime diary.  

Just before entering Aberdeen, about two miles along the road from the place I reached it, I ran into a barbed wire entanglement.  I immediately thought that the Japanese must be at Aberdeen and that I should be captured and probably die of pneumonia if not shot, which I thought was very discouraging after all my efforts.  

Im sure this is known about, but it was'nt marked. (GPS coordinates are Aprox)

Regards