Square Rock is number 4 on the Namadgi National Park map, Walks on walking tracks.  It is rated as 8.5km return (4 hours), but can be completed a little quicker than that if so desired.  2 of us completed this walk.  It is a wonderful introduction to the bush around Canberra, easy walking and quite a spectacular view.  This walk is described in more detail here.

We then drove to Corin Dam and walked down to the bottom of the face of the dam.

On the way back to Canberra we called in to Gibraltar Falls for a peek.

Distance: 8.5+1+1km  Time: 8.00am-10.00am; 10.15-11.10; 11.25-11.40am.