PF Cell at Lung Fu Shan

What's this for? It doesn't look like for storage of ammunition with the curved top frame ...

In general terms the PF Cell was the early form of rangefinding for individual Batteries, being divided into areas for the specific equipment and controllers. They were superceded by the introduction of the Fortress Rangefinding System in the 1930's, which allowed centralised control of all Batteries. They may have had secondary uses after that, not the least for those in the Mt Davis area as squatter accomodation. Modifications to the original structures probable.

Thanks for the information. What does this feature look like to you?

Sorry, don't have an explanation.