According to The Guardian, the border between Switzerland and Italy has shifted due to the melting of the Theodul glacier in the Alps. This called into question the location of the Italian hotel-restaurant Rifugio Guide del Cervino, part of which technically ended up in southern Switzerland.
The glacier is located south of Zermatt in the canton of Valais. It lost almost a quarter of its volume between 1973 and 2010, exposing a rock under the ice and changing the watershed, forcing the two neighboring countries to move a 100-meter section of the border.
The Italian-Swiss border runs along a drainage divide, a point at which meltwater flows down both sides of a mountain towards one country or the other. But the retreat of the Theodul Glacier has shifted the watershed to the Guide del Cervino, where restaurants, a hotel, and a lookout are located.
The issue of moving the border has been the subject of diplomatic consultations since 2018, they ended in a compromise in 2021, but the details of the agreement were not disclosed. Currently, the displaced border is indicated by a dotted line on maps.