Barcelona is a dense and compact city with 1.6 millions of  habitants. The Department of Urban Services and Environment offers a set of environmental education programmes, activities and resources to the education sector and also to all city residents with the intention of spreading awareness of the city's environmental management and of stimulating residents' complicity and involvement in its enhancement.

One of this programs is Barcelona Schools Agenda 21 Program that involves the community and network of Agenda 21Schools and creates new projects linking environmental education and skills for a green economy. 

http://www.bcn.cat/agenda21/
With several guides of Sustainability