I was sad when I read that these snazzy-looking bird nests were placed around Madrid only as part of an art project. They look like every bird's dream home—modern, sturdy, and weather-resistant.
The nests were actually modifications of the odd "yellow balls which are put in place to avoid accidents with scaffolding joints" and they seem like a fantastic idea. No reason that those balls couldn't serve as temporary bird homes now and then. [LulzInterruptus via Dude Craft via Neatorama]