No shadow building

Le Project Triangle is one of those buildings that make us think that we may actually drive flying cars one day. To be completed by 2014 in the Porte de Versailles area in Paris, its most impressive feature is that, according to the architects, it won't cast shadows on adjacent buildings. The trick is the orientation and it's shape: While it looks like a massive pyramid from one side, the other side shows that it really is an ultra-thin triangle resembling a shark's fin

More here