Tourism is not only an economic sector but at the same time, has social, cultural and environmental impacts on host communities, tourist-sending countries, and tourists. Cultural tourism in general and cultural routes as an important component of cultural tourism offer a big potantial for a sustainable tourism development. Besides economic, socio-cultural, and environmental benefits for host communities, cultural routes play an important role in mutual understanding and exchanges across boundaries. The paper particularly focuses on solidarity, mutual understanding, cultural exchange, inter-cultural dialogue, and cooperation features of cultural routes. In the second part of the paper, as a case study some established contacts, project proposals, and initiatives between Southeast European countries are tried to explore by some examples.