Japanese Tunnel in the village of Tung O [????- ]
I was shown how to get to this tunnel by our event host, Robert, who has lots of knowledge about Lamma Island, after a beach cleanup with the Hong Kong Hiking Meetup (https://www.meetup.com/hongkonghikingmeetup/events/238825314/) .
It is difficult to locate the tunnel on the map, so the coordinates shown may be a bit off.
To get there using Shek Pai Wan (which we cleaned) as a starting point, go south on the concrete footpath and turn right to get to Tung O village. (This path goes all the way to beautiful Sham Wan, where sea turtles lay eggs).
Somewhere along the way, you will see a banyan tree growing on top of a big piece of rock. Just before you get near this rock/tree, turn right (if I remember correctly), and you will see the view in the photo. Go behind the house and you will see some ruins. Go behind the ruins and the tunnel entrance is on your left.
Bats and other inhabitants are inside. They are harmless, according to Robert, so please don't harm or disturb them.