Eerily standing on Beechey Island, a peninsula off Devon Island in the Canadian Arctic, are four lonely graves: three members of an ill-fated expedition to the Northwest Passage, and one of the men who went looking for them.

In 1845, Sir John Franklin led an expedition to find the Northwest Passage, a direct route from the Atlantic Ocean to the Pacific Ocean across the arctic, on two ships that were called “unstoppable” at the time. They were stopped, though the exact circumstances remain murky.

The expedition stopped off at Beechey Island for a winter encampment. Here, three of the 130-person crew are buried near the shore, on an otherwise desolate plain. The rest of the crew abandoned the ships after leaving the encampment when they got stuck in the ice near King William Island. Evidence of them, and the fact that they resorted to cannibalism, was later found.

How the three young men died is still unknown, despite the fact that their bodies remained remarkably well preserved—essentially mummified—in their coffins in the freezing arctic ground. John Torrington, William Braine, and John Hartnell were exhumed in the 1980s as part of an anthropological examination of the site. They were later reburied.

Lead poisoning from their canned food was a leading theory, though it is disputed now. In recent years, both of Franklin’s ships have been discovered, and it is hoped that more mysteries can be solved.

The fourth grave marker at the site is that of Thomas Morgan, who died a few years later on one of the many expeditions to find out what had happened to Franklin’s expedition. Each grave is made of wood with bronze placards, recreations of the original markers.