founded in Madrid in 1876, introduced in Spain the perspective of modern view of the geographical landscape, initially promoted by Humboldt.This modern way of seeing the landscape was associated with an equally modern conception of the excursions, which occupied a very prominent place in the intellectual and educational horizon of Giner and the Institución.Excursions paid much attention to the natural aspects as historical, monumental and artistic features of the landscape, and were both expressed exemplary in their approaches to La Granja de San Ildefonso, in the Sierra de Guadarrama.This article, supported by analysis and contextual interpretation of texts of diverse nature related to the topic, studies the key of the assessment of those natural and historical aspects of the landscape of La Granja de San Ildefonso in the successive approaches to the place of the Institución Libre de Enseñanza, from his first excursion to the Sierra de Guadarrama in 1883, until the eve of the last civil war.