Ever wondered what it would look like if Manhattan was transported to the Grand Canyon? Probably not, but after a trip to the United States last year Swiss photographer Gus Petro was determined to find out. The project is the last in a series called "Empty, Dense, Merge" which explores the juxtaposition of emptiness and density in the US by combining the arid deserts with a bustling metropolis. "The contrast between the two was so strong and overwhelming that I had to express it somehow," says Petro, who took photographs of the two sites from matching perspectives and then painstakingly Photoshopped them together. "After showing the images, most of the people who haven't been in either place thought it was real," he says. "They began questioning me where it is. I didn't expect that for sure."