One of my favourite pieces from Art in the Dark was Emilie Priest's Miniature Cities. There is a plastic mountain the size of Texas growing in the Pacific called the Pacific Gyre, which is having catastrophic effects on the natural world. Emilie's work responds to this, in the hope that a small act can affect a huge problem. She has made a series of beautiful miniature cities which can be found in four of central Auckland's waterways. Each site has a response code which allows you to activate the a small act website. Emilie's works are truly captivating; see more on her tumblr, website, or better still, have a real-life look at her delicate, watery cityscapes around Auckland.
Images of Minature Cities by Emilie Priest (2010) at Art in the Dark by Hans E Hammonds (top) and Elizabeth Clarkson (bottom).