Military construction? [????- ] | Gwulo: Old Hong Kong

Military construction? [????- ]

Current condition: 

Didn't expect to come across this building hidden among thick vegetation with a wide trench nearby.

IMG_20200904_facade.jpg, by H.Lo
IMG_20200904_roof.jpg, by H.Lo


I wonder if it is a single structure, or perhaps like nearby Ki Lun Shan, lots of associated trenches and bunkers?

Probably, it's the first time we were up there.

We were in a hurry, but believed there should be some more ruins on those hills.

This one was facing south, with a terrace like level ground facing north between the trigonometry pole and this construction.

There's a narrow trench near another peak where one of the two flagstaves was.