Photographer Petr Mesi spent four months producing this fast-paced timelapse video, which highlights the stream of boat traffic which passes over the Chicago River between April and June when the bridges are traditionally lifted. The Chicago Department of Transportation lift the city’s 27 movable bridges one by one, allowing for ‘boat runs’ like that featured in the video to take place. This video captures the city’s energy in a unique way. Credit: YouTube/Petr Mesi