The city of Assisi along with almost all its territory was added to the World Heritage List in 2000.
In its justification, UNESCO stressed that
Assisi represents a unique example of continuity of a city within its environmental setting and territory.
The World Heritage Committee decided to inscribe the
City of Assisi, the Basilica of San Francesco and Other Franciscan Sites on the Unesco World Heritage List on the basis of the following criteria:
Inscription N° 990 2000 C (i) (ii) (iii) (iv) (vi)
Criterion (i): Assisi represents an ensemble of masterpieces of human creative genius such as the Basilica of San Francesco, which have it a deep fundamental reference for art history in Europe and in the world.
Criterion (ii): The interchange of artistic and spiritual message of the Franciscan Order has significantly contributed to developments in art and architecture in the world.
Criterion (iii): Assisi represents a unique example of continuity of a city-sanctuary within its environmental setting from its Umbrian-Roman and medieval origins to the present, represented in the cultural landscape, the religious ensembles, systems of communication, and traditional land-use.
Criterion (iv): The Basilica of San Francesco is an outstanding example of a type of architectural ensemble that has significantly influenced the development of art and architecture.
Criterion (vi): Being the birthplace of the Franciscan Order, Assisi has from the Middle Ages been closely associated with the cult and diffusion of the Franciscan movement in the world, focusing on the universal message of peace and tolerance even to other religions or beliefs.