Novak's "theory of education" (1977) has become very significant to foster environmental education. The theory proposes teaching techniques that buid on the meaningful learning theory (Ausubel, 1968), and on the theory of constructivism. Novak's theory proposes an educational system that promotes changes in behaviour, attitudes and values, which are also inexcusable aims of environmental education. One of Novak's key proposals is the use of concept maps during the educational process. The aim of this doctoral dissertation is to analyse Ausubel and Novak's constructivist theories of meaningful learning together with the theoretical framework of environmental education and museology, looking for educational proposals that stem from therse complementary disciplines. The results of the analysis have been applied to support and develop a coherent teaching unit for schoolchildren aged 11 and 12, that uses as educational resource the Natural Sciences Museum of the University of Navarra. The teaching unit aims to foster higher-quality longer-lasting learning processes, based on a more truthful environmental-science base, and to have a positive influence on the environmental behaviour of the targeted students, improving their environmental attitudes. The unit has also been designed to make the best use of educational advances in the field of the new technologies.