This is a recreation-based reserve that sticks out into Lake Burley Griffin. There is plenty of parking, but it might get a bit full on weekends when the weather is good.
There are good footpaths/cycle paths along the water and its pretty easy to leave the path and walk down to the water's edge.
A few rowing clubs have facilities here, so it is common to see rowers out on the lake or in the process of going out or coming in. At the moment there is some construction going on between the rowing clubs and the water as new ramps and docks/pontoons are being built.
There is an inflatable aqua park here that is probably only open in the warmer months when the blue-green algae levels in the lake are ok.
There are toilets, tables, and bbq areas here. Also playgrounds for the kids.
The road (Garryowen Drive) into the recreation area is off Lady Denman drive just below Black Mountain.
You can follow this r0ad to the roundabout at the end or take one of the side roads. They all seem to have parking at the end.
Good paths for walking
Looking inside on of the rowing sheds
The Aqua Park was closed when I was there last.