I’m going to be honest here and say I got this one pretty wrong. Looking at Google Earth, Big Monks is about 1.7 km from the access road (which I got right), what I failed to notice is that it is super steep and that much of the walk is off the trail. So… A walk I thought would take 30 or 45 minutes took 2 hours. I didn’t die though, so that’s good.
Fantastic views at the top, and found a couple of geocaches. There is obviously a lot of walking potential in Rob Roy Nature Park.