There used to be an Engineer's house in this part of the glen and the water channel here ran through its garden There is a Water lock//hatch in this channel this is what you are looking for to find the cache, lots of overgrowths here it can get tight PLEASE BE CAREFUL.
The following is a paragraph written in a Glen Centre pdf on a man named Gerard O'Brien about Growing up in the Engineer's House:
Activity in the Glen was mostly connected to the water. There was fishing (for incurable
optimists), rafting, and until the early sixties, swimming. There were always particular spots
that formed the focus of these activities. Just outside our gate, where nowadays, two timber
frames straddle the overgrown river, there used to be a ford where the river broadened and
shallowed between the deep channel that ran through our garden and the deep water of the
‘Hatch’ downstream. I remember this as a place where the sandy soil was always exposed from
the constant movement of feet. There were stepping stones so you could cross the water,
but it was also a safe place for paddling, fishing for ‘thorneens’ and building dams out of the
riverbed stones and waterweed. These were simple activities that never went out of fashion—
all you needed was a fine day.