A border on the move

Along the high Alps, the border between Switzerland and Italy follows the drainage divide: where meltwater runs north or south. On the Theodul Glacier near Zermatt, that divide lay on ice.

As the glacier melted, the divide crept under the Rifugio Guide del Cervino at Testa Grigia, putting much of the hut technically on Swiss ground. Negotiations began in 2018, and in November 2021 the two countries reached a compromise. In the words of swisstopo’s chief border official: “We agreed to split the difference.”