This year they have a brand new scuplture in the garden, its called the Skyspace.
There is a man made lake in front of the gallery, a giant mound covered in native grasses has been constructed, you walk in, along a path seeming to float into the water - inside the mound there is a square of blue water with a stone tower in the middle, you walk into the tower, its a rounded smooth stone cave, with heated stone benches around the edges, a circular mosaic on the floor. You sit on the warm benches (very nice in Canberra in winter) and then you look up to see this!
A small hole lets in a constantly changing glimpse of the sky.
It is awesome.
It may be my new favourite thing at the gallery, although the fog sculpture has long since been my favourite and its hard to top the waves of fog rolling across a reedy pond. I love that something so intangible as mist can also be defined as something as solid as a sculpture and defined as art.
There are many pieces in this garden, if you haven't visited you should do so.