There's a town in Italy that doesn't get sunlight for 84 days a year. They've solved this problem with a giant mirror

Call it the reverse Montgomery Burns scheme. The little town of Viganella is located amidst the Italian side of the Alps. During the winter time, the shift in the sun's pattern makes it so that it never clears the 1600 feet tall mountain that's close to the town. This means that for 84 days, they do not get any sunlight. The townspeople end up suffering from Seasonal Affective Disorder, a type of mild depression. 

To solve this, the government installed a massive mirror on the side of the mountain. It measure 26x16 feet and is computer controlled to follow the trajectory of the Sun. The result is that starting in 2006, the town was able to celebrate the first winter sun in 600 years!