Chris Drury is one of my favourite Eco Artists. He has built installations around the world working with aperature to create camera obscura architecture - basically his outdoor installations create an inverted image of the natural world outside and projected inside his installation.
Here are some pics:
Cloud Chamber for the Trees and Sky
here is the outside image of the trees reflected inside his installation
Click on image to follow links of how "Wave Chamber" was designed
visit Chris Drury's site