There is a festival called Lux Helsinki which runs during the Christmas period.
I think it is similar to Vivid Sydney, but 20 degrees colder.
They were just starting it, by blocking roads and illuminating the cathedral at 5pm when it is already dark, but people were still working in the city.
What I saw was the simple beginning of the show, but it’s getting very cold and I didn’t want to stay longer to see the full show. Clearly I’m a wimp, because there were several couples going to Lux, pushing a well rugged up infant in a stroller…..”this is what -20C feels like, young fella”.