As a highly walkable city, Sheffield has a number of pedestrian-facing dOOH boards that you can use to reach customers either living or working near the CBD area. The Urban Panel network of Clear Channel Outdoor and Global collectively covers the entire city. Going outwards from there, you'll find a series of billboards along arterial roads - in addition to some attractive landmark billboards from my friends at JCDecaux - the Sheffield Towers.
Like Google or Meta ads, I'm an self-service ad platform.
All you have to do is make an account to get started.