It's the word "Barracks" that gives it away on Google Maps.
LUcky you have a conference that is so continuously interesting. I only had one of those in my life, and I had to go to the US to take part. My problem was I was swimming in a very small local pond.
And the barracks will soon become more extravagant real estate as it's being sold off.
You could run the N side of the river. Cross on the newer, Eastern bridge, then go under it and follow the path. Ask Noel to send you the North Freo orienteering map. Oawa.mappingatgmail.
It's 'being sold off' for years now.