Last week I had a mooch around Pok Fu Lam reservoir and came upon some bunkers. As you first walk into the reservoir you go past a badly damaged bunker, before you reach the public toilets there is a rubbish bin, behind which is a set of stairs leading up to these bunkers.
They were once bricked up but you can get into most of them. You can follow the stairs up further to what appears to be the observation/command post .
