The sociologist Mario Gaviria passed away in Zaragoza on 7 April, about to turn 80. He was a social activist and pioneer of urban sociology in our country. Gaviria studied Law in Zaragoza and Economy and Sociology in France and the UK. When he returned, already as a disciple of Henri Lefebvre, he introduced in Spain the most advanced trends in sociology and tackled new issues like leisure and tourism, before several stays as researcher in California, where he became imbued with the American environmentalism of the time. Establishing a connection between the sociological avant-gardes and the Spanish tradition of Joaquín Costa, Gaviria contributed as few others in our country to creating an ecological conscience, and had a fruitful career teaching in pioneering institutions like the Escuela Crítica de Ciencias Sociales and developing an interest in territorial planning, exerting an influence on several generations of architects, and analyzing topics like the cities of leisure – he was the first to defend the importance of Benidorm – or agricultural policies – condemning the ‘España vacía.’ Gaviria received the National Environment Award in 2005.