The Seattle Art Museum (SAM) opened a new sculpture garden early this year. It's on the north side of Seattle on a hill overlooking Puget Sound. It has a number of prominent sculptures, including this Calder stabile. According to Wikipedia, Calder invented the mobile and the stabile. Who knew?
The tree in the foreground is not actually a tree, but another sculpture. I did a little research and found it is called Split, by Roxy Paine. This is an interesting piece because it sneaks up on you - in the winter, it looks like just another leafless tree. But take a closer look and the truth is revealed.
SAM has a virtual tour of the garden here. This photograph was taken on the opening day of the garden January 13, 2007.