It is covered in graffiti. There are multiple compartments, a ladder up to the top and another ladder going down inside. There is a hopper like arrangement on one end.
I could not figure out how it would have worked or exactly what it was used for. Maybe for purifying water from the river or maybe for treating sewerage, who knows? I would be most interested in what others might think of it.
Whatever it was, it is now a great place to hide a cache.
The easiest access without entering private property is from the end of Janefield Drv taking the path that runs down behind the houses in Zara Close. Access is possible from other parts of the park but may involve bush bashing.
It is a small cache containing the log and a pencil. There is room for small swaps or TBs.