This document summarizes the work of the Infoplàstica group, a class of 20 students from St. Pau Apòstol school in Tarragona, Spain. The group discussed the origins of legends and who invented them, developing over 50 notes on the topic in Knowledge Forum. They concluded that legends stem from strange real events and facts mixed with fantasy to make them interesting. Legends have collective rather than single authors and change over time through oral tradition. The group then divided into 4 teams to invent new legends about their local Francolí river, recording videos of the legends.