sai wan fort tunnel [c.1943- ]
one of two tunnel systems I found skirting round Sai Wan Fort. This one has two entrances, one overlooking what was the bay of Sai Wan. Fairly extensive. The main entrance is easy to find (once you get there): on the road up to the fort, head north around the hill from where there is some construction next to a resting area. There is a few minutes of bush whacking but there is a path created by workers who've been making the hillside safer. Below is a large metal fence to stop falling rocks, while next to the entrance a large boulder has been conspicuously shored up with a concrete wall. The other tunnel system, which is more extensive still, is around the same height but further north.