Few teachers are remembered beyond the lifetime of their students, and fewer still when their specialty is the history of education. But one exception to this rule is Dr Josep Estalella (1879–1938), whose lifelong involvement with active learning resulted in enduring contributions to teaching methodology and teaching resources. Estalella’s commitment and leadership as director of the “Institut-Escola”, the Government of Catalonia’s progressive secondary school of the 1930s, made pedagogical change possible in Catalan secondary education. One hundred years after it was originally published, Estalella’s Ciència Recreativa (Recreational Science) is still considered to be a valuable teaching resource for helping children develop intellectually through play.