The Falkenberg Encyclopaedia results from a public art project for a school and library in the Swedish coastal city of Falkenberg, commissioned by Public Art Agency Sweden & Falkenbergs kommun. In collaboration with adults and young people from the city, I set out to investigate how knowledge is sorted: which subjects are shelved within the library, what lessons are taught in the school, and what – ultimately – has been left out. Together we explored what we know, what we think we know, and what we may need to know in the (as yet unknown) future. Through discussions, games, mapping exercises and workshops, I engaged local residents in wide-ranging conversations which formed the basis of The Falkenberg Encyclopaedia. The book reflects a deliberately incomplete catalogue of unrecognised, unvalued, underappreciated, rejected, and forgotten knowledge, asking the reader to remain conscious of the gaps and absences in a taxonomic system such as this.