We've looked at the tunnels built by the British before the war , but how about those built during the Japanese occupation?
The Japanese dug a variety of tunnels throughout Hong Kong. Some, like the tunnel near Diocesan Boys School , were used to store ammunition and explosives. Others in the built-up areas  were likely built as air-raid shelters. Then out in the countryside, many smaller tunnels were dug into hillsides . These were likely prepared against possible invasion, and would be used by Japanese soldiers fighting a guerilla war.
I expect the tunnels in the built-up areas have long been dug up, filled in, or just forgotten about. But out in the countryside they are often left untouched, and lie next to hiking trails. I'm hoping you've seen some that you can let us know about.
Here is a map of the tunnels I've seen - only four so far, so we definitely need some help to add more.
To add another tunnel to the map, click the 'add another tunnel' link above, and be sure to put japanese tunnel in the Tags: field. Then after you click the 'submit' button it will be added to this map. If you're adding a tunnel in the countryside, please include a description of how to find it in the Notes:, as it's not always easy to see where they are on the satellite image.
I'd also love to hear any stories or memories you have about these - who built them (POWs? local workers? etc), what the tunnels were used for, etc.
 Map of wartime Air-raid Precaution tunnels built by the British
 Japanese tunnels, Diocesan Boys School
 Japanese tunnels, Former Marine Police HQ
 Japanese tunnels, Buffalo Hill and Mount Cameron