Despite its relatively small area European territory has many mountain ranges located in most of the countries. Land development in separate mountain ranges has a tendency to diversify. Not only is this phenomenon evident in regions with a great increase in agricultural, service sector, tourist and industrial functions, but also in regions which are agriculturally worthless and less economically valuable. Even though mountain areas in Europe are inhabited by more than 15% of population, the diversity of both particular countries and mountain ranges is large. Mountain areas, particularly in EU–15 countries, Switzerland and Norway, are as a rule poorly populated, while in Poland, Slovenia and Hungary these tendencies are disparate. Frequent phenomena facing mountain areas in Europe are an ageing of the local population and the rural depopulation. Mountains are of great significance for both the population and the diversity of continent’s fauna and flora, besides, the natural resources of mountains are described as “the undervalued ecological backbone of Europe”. The greatest value of mountains is attributed to their cultural diversity because mountainous areas are inhabited by numerous ethnic minorities differentiated by their culture, language, dialects and tradition. It should be noted that functions of mountains and their contribution to both the development and the living conditions of local population can be diversely classified. These functions, which include environmental, economical and sociocultural ones, have been known for ages. They can also be divided into the green – connected with nature, the white – connected with health care, the blue – concerned with water and the yellow – concerned with life-span and economic development. Sustainability of strong demography units is the key precondition for the maintenance of natural and cultural richness, as well as for the economic significance of European mountains.