They arrived on Sunday in parkas and ski hats, hiking across the rocky terrain where Iceland’s Okjokull glacier once flourished. Today it is a watery grave, which scientists and politicians say is the site of the nation’s first glacier lost to climate change.

A lake of melted ice now dominates the landscape amid a barren stretch of stone and dirt. The site was renamed to Ok after “jokull,” meaning “glacier” in Icelandic, was dropped.

In 2014, Oddur Sigurosson, one of the country’s leading glaciologists, declared Okjokull dead, saying the ice was too thin for it to qualify as a glacier. To mark its end, Icelanders unveiled a bronze plaque with a warning: “In the next 200 years all our glaciers are expected to follow the same path.”

Iceland is not the only place where glaciers face extinction, but a rise in global temperatures poses an existential threat to one of the country’s signature attractions. Glaciers cover 11 percent of Iceland and are prominent attractions and sources of tourism.