To be inscribed on the UNESCO World Heritage List, UNESCO World Heritage properties must be of Outstanding Universal Value and meet at least one of ten selection criteria. The Rhaetian Railway in the Albula/Bernina Landscapes meets criteria II and IV for its inscription.
Criterion (ii): The Rhaetian Railway in the Albula/Bernina Landscapes constitutes an outstanding technical, architectural and environmental ensemble. The two lines, today unified in a single transalpine line, embody a very comprehensive and diversified set of innovative solutions that bear witness to substantial interchanges of human and cultural values in the development of mountain railway technologies, in terms of its architectural and civil engineering achievements, and its aesthetic harmony with the landscapes through which they pass.
Criterion (iv): The Rhaetian Railway Albula/Bernina is a very significant illustration of the development of mountain railways at high altitudes in the first decade of the 20th century. It represents a consummate example of great quality, which was instrumental in the long-term development of human activities in the mountains. It offers diversified landscapes in conjunction with the railway that are significant of this period of the flourishing of a relationship between man and nature.
The railway infrastructures of the Albula and Bernina lines form an authentic ensemble of great integrity. Their technical operation and their maintenance ensure long-term conservation of high quality. The Rhaetian railway company that has unified them and carries out their technical management has introduced technical changes and innovations that are compatible with the concept of authenticity of technological properties that are still in use.
Authenticity & integrity: The property comprises the railway line as a technical monument as the core zone and - in the buffer zones - the surrounding landscape. The railway lines and their surrounding landscape form a harmonious art of work. The Alpine natural and cultural landscape encompassing the World Heritage in the buffer zones is exemplary for the railway development concerning the opening up of the Central Alps at the beginning of the 20th century. The property thus preserves all the necessary elements to express its exceptional universal value.
The cross-border perimeter of the property reflects all the mutually influencing structural, technical, cultural and natural factors of the railway phenomenon in a wider context. Although technical modernisations have to be made possible to ensure the functioning of the railway over a long period of time, the exceptional universal value of essential attributes of the World Heritage Site is conveyed in a credible and authentic way.
It is evident that technical modernisations that guarantee the functioning of the railway over a long period of time must be possible. They are tantamount to a development of the monument, as they are also recognised for any "classical" monument.
You can find further information at whc.unseco.org.