The Afsluitdijk is a 20-mile dam that has been protecting the low-lying Netherlands from the force of the ocean for decades. According to Daan Roosegaarde, a Dutch artist who works in urban environments, it’s quite famous in the country because “basically, it protects us from drowning.”
Roosegaade recently installed the “Gates on Light” on 60 massive floodgates split between both ends of the dike. Because of sea level rise, the structure is in need of renovation. Roosegaade wanted to use this opportunity to draw attention to the importance of the dam—which many take for granted—as well as to another environmental issue: light pollution.
According to the World Atlas of Artificial Night Sky Brightness, more than 80 percent of the planet’s land area, and 99 percent of the populations of the United States and Europe, look up to skies so polluted with light that the Milky Way is virtually invisible. Amsterdam’s skies are some of the most light-polluted in the world.