It’s hard to believe that it’s been over two decades since Harry Potter first came into our lives – and exactly 20 years since the first release of the Chamber of Secrets.

We worked with Bloomsbury Publishing on a special anniversary campaign to spread the word throughout London that it’s been 20 years since the Chamber of Secrets was first opened. The colourful artwork for the brand new celebratory Hogwarts House editions came to life through this 4 sheet takeover campaign, allowing passersby to pick their true colours. So whether you’re a wise Ravenclaw, hard-working Hufflepuff, cunning Slytherin, or a proud Gryffindor, be sure to choose wisely.

Find out more about Harry Potter at 20.