Inverted siphon no. 1, Pokfulam Conduit [c.1877- ]
Part of the original Pokfulam Conduit, the inverted siphon carried the water across the valley through a pair of cast iron pipes.
The conduit was later extended to cross the stream further inland via a new bridge and the inverted siphon was no longer needed. The pillars that supported the inverted siphon's pipes have survived and can still be seen.
For more information see: https://gwulo.com/node/54774