The exhaust tower is 160 meters tall, with falcon nesting nooks built into the top by Hundertwasser himself. These have been continuously occupied by falcons for many years. The plant workers are very fond of them.
Every detail of the plant was designed by Hundertwasser in his particular organic style. Looking at some of the post-war Stalinist architecture here in Vienna, you can easily understand what he was reacting to. I would be tempted to decorate those concrete boxes myself!