In the town of Rjukan, Norway, people gather in front of the town hall, where sunlight is reflected by giant mirrors (top) erected on the mountainside, on October 18, 2013. Rjukan, a small industrial town 150 km west of Oslo, is situated in the bottom of a valley between steep mountains in Telemark County, and is cut off from direct sunlight for five to six months a year. Now, three giant mirrors mounted on a nearby mountainside will reflect winter sunlight into the valley. #

Giant mirrors erected on a mountainside reflect sunlight into the Norwegian town of Rjukan in the valley below, on October 18, 2013. Combined the mirror surfaces are about 51 square meters (549 square feet). #

Heliostats, computer-driven motors, control the position of Rjukan's giant mirrors, following the Sun's path to reflect sunlight into the valley below, on October 18, 2013. #

People gather in front of Rjukan's town hall, in sunlight reflected by giant mirrors erected on a mountainside some 450 meters (1,475 ft) above the small town, on October 18, 2013. Rjukan, located in the bottom of a valley between steep mountains in Telemark County, is normally cut off from direct sunlight for five to six months a year. Now, the three mirrors will bring winter sunlight into the valley. #

In Italy, in the steep Antrona Valley, the small town of Viganella sits under a banner reading: "Viganella vi da il benvenuto" (Viganella welcomes you), on December 17, 2006. On that day, Viganella celebrated its "day of the light", as it officially inaugurated a giant mirror positioned on a nearby peak to reflect sunlight onto the town's square. The 197 inhabitants of Viganella used to suffer from a complete lack of direct sun from November to February, but the eight-by-six meter sheet of steel, remotely controlled by a computer will now reflect the sunrays to the town's square during the winter. #

Pierfranco Midali, the mayor of the small town of Viganella, in Italy's Antrona Valley, claps his hands as the giant mirror positioned on the hill behind starts reflecting the sun, on December 17, 2006. #

A mirror, an eight-by-five meter (26x16 ft) sheet of steel, is placed on a peak overlooking Viganella, Italy, to reflect sunlight onto Viganella's main square, on January 24, 2007. #

Locals and visitors enjoy the rays of sunlight brought by a 40 square meter tailor-made sheet of steel on the peak of the 1,100 meter high Mount Scagiola above the tiny village of Viganella in the Italian Alps, on December 16, 2006. #