Old sub-terrain public toilets?
It seemed a bit odd to have such a topic but indeed it was one of those totally unexpected during our meet-up over dinner. Would you be more astonished if I tell you the topic was raised by the only lady present? :-P
I could not recall anything like these on Kowloon side, but I have been peeing into at least three of them occasionally back in the 1970's. They have one thing in common, ladies are not allowed.
Of the three mentioned, one of them was under Pottinger Street, the second one was at the junction of Wellington Street and Queen's Road Central. The last one was located in Queen's Road West at what we localls called 雀仔橋 (Pronounced as Tseuk Jai Kiu. If you must translate it would be something like Birds' Bridge. Today, only the one at the junction of Wellington Street and Queen's Road Central still functions as a Toilet. Gone was the days when a long trough running all the stalls with water being flushed periodically from one end to the other carrying everything in the middle with the flush. All the old utinsils had been replaced. It had been modernized in the past decade or two.
The one under Pottinger Street is already covered in another forum article so I am not going to repeat it. It had been made into sort of a store room, but the ventilation shaft could still be seen above street level.
The other one that had been bricked up could be seen in this Street View photo:
Those five blocked up windows used to be the windows of the toilet. The entrance wa on the top toward the western side.
The still functioning one could be view here:
Can you see it? This angle was also the same one for a very famous sketch of an old shop house which looked like it had been suddenly being cut in halves with a curvey end on one side and the straight end along Wellington Street. I believe that sketch was by Mr Kong Kai Ming too.
Actually all three of the toilets are well above sea level so you don't have to worry about where did the flush go or if the seasonal high-tide would throw everything back through the conduits.
My 2 cents,