When we envision the world’s greatest cities–from San Francisco to Sao Paulo to Paris to Tokyo–we usually picture bridges and towers and cathedrals: the built environments that have left lasting impressions on our mind’s eyes. The irony being that those skylines have been in place for at most a century or two; the sky above has looked the same for millions of years.

Our greatest cities are often the sources of the most light pollution. In those places, we rarely see the stars. But, with a clever method of composite imaging, the French photographer Thierry Cohen has turned the lights out in the city to reveal the stunning stars that have always been overhead.

Editor’s Note To see a city plunged into real darkness, check out these eerily gorgeous photos of New York during the post-Sandy blackout.

In his series “Darkened Cities,” Cohen creates a visual reminder of what the world would look like if it were free of light pollution, and asks us to ponder how an increasingly urban society can disconnect us from the natural world. So how does he create the images? New York’s Danziger Gallery, which will feature his work beginning on March 28, explains:

Cohen’s method is original and precise and harkens back to the methodologies employed by early 19th century photographers like Gustave Le Grey. He photographs the world’s major cities, seeking out views that resonate for him and noting the precise time, angle, and latitude and longitude of his exposure. As the world rotates around its axis the stars that would have been visible above a particular city move to deserts, plains, and other places free of light pollution. By noting the precise latitude and angle of his cityscape, Cohen is able to track the earth’s rotation to places of atmospheric clarity like the Mojave, the Sahara, and the Atacama desert. There he sets up his camera to record what is lost to modern urban dwellers.

By linking those two images, Cohen connects contemporary landscapes to the geometry of the stars (each image title includes corresponding longitudinal and latitudinal coordinates). In doing so, he not only juxtaposes the density of our tiny, crowded cities with the vastness of the universe, but also suggests that all our lights will one day fade. While we’re here, we owe it to ourselves to consider what’s been here all along.