Copenhagen Christmas via Inhabitat
Barcelona (cones) Trees via Wired
Milano Carouselle via Design Boom
Lots of joyful pedal-power installations are popping up in cities around the world this holiday season...
Copenhagen, Denmark (top) might be taking the lead with 15 bicycles in the City Hall Square lighting up 700 LED bulbs that a 17-meter-tall evergreen.
In Barcelona, Spain (middle), once the sun sets you can hop on a bike and contribute to powering the LED adorned Christmas tree in the central Mercat Santa Catarina square.
While in Milan, Italy (bottom), Carouselle by Ignacio Ojanguren Alvarez, Christina Perdikaki, and Hafsteinn Juliusson. By pedalling the stationary bikes you light up the over sized lamp!