The exten­sion of the nat­ur­al World Her­itage prop­er­ty of Jungfrau — Aletsch — Bietschhorn (first inscribed in 2001), expands the site to the east and west, bring­ing its sur­face area up to 82,400 ha., up from 53,900. The site pro­vides an out­stand­ing exam­ple of the for­ma­tion of the High Alps, includ­ing the most glaciat­ed part of the moun­tain range and the largest glac­i­er in Eura­sia. It fea­tures a wide diver­si­ty of ecosys­tems, includ­ing suc­ces­sion­al stages due par­tic­u­lar­ly to the retreat of glac­i­ers result­ing from cli­mate change. The site is of out­stand­ing uni­ver­sal val­ue both for its beau­ty and for the wealth of infor­ma­tion it con­tains about the for­ma­tion of moun­tains and glac­i­ers, as well as ongo­ing cli­mate change. It is also invalu­able in terms of the eco­log­i­cal and bio­log­i­cal process­es it illus­trates, notably through plan suc­ces­sion. Its impres­sive land­scape has played an impor­tant role in Euro­pean art, lit­er­a­ture, moun­taineer­ing and alpine tourism.