Urban design fanatics can rejoice in these pictures from German photographer Nick Frank, who stalked Munich's subway stations after hours to capture the eerie, modernist beauty of underground architecture in his hometown. Frank, who works as a creative director at an ad agency by day, has an eye for bold, basic shapes and bright colors.
"I really have a graphical and minimalistic eye because of my main profession," he said. "From my point of view, photography is all about reducing the image as long and as much as it takes until the essence has become visible."
Check out more from Nick's subway series on Behance.