Access to cultural heritage constitutes the core behaviour of a society which aspires to be inclusive and barrier-free. Taking part, experimenting, the historical architectural heritage is the essential condition for conscious and active participation in the modern society that is founded and enriches the common identity. The concept, and the consequent project, of accessibility, represents the keystone of the inclusive process. The application of the principles of Universal Design is, therefore, the operational translation for the conservation, improvement and development of those places that represent civilizations and their cultural, urban and landscape development. In order to be able to develop and increase this awareness, it is necessary to operate through a design input that has its roots in consciousness that we could call true sustainability. The new anthropological approach, as a founding method of Universal Design, has focused attention on participation, so that the user is an active subject and the environment must be designed not only to reduce the experience of disability but above all to improve everyone’s experience and performance. The principles linked to inclusion can, therefore, be interpreted as a new perspective for architectural design and planning to respond to the new demands of society. The above-mentioned aspects are explained by showing some significant examples.