A Norwegian town built a giant mirror to deflect the sun (2017)
This is sort of off topic, but this valley is pretty famous actually for being a strategic place in World War II (but not widely known) because it was a crucial source of heavy water.If you haven't seen it already, I'd highly recommend the Netflix series "The Heavy Water War" (trailer: https://www.youtube.com/watch?v=_K3Ry2K4yNE)