In May 1950, two Danish farmers were cutting peat in Tollund Fen, in the middle of the Jutland Peninsula, when they found a man’s body. His skin was stained a deep, tawny brown, and he was wearing a pointed cap. Around his neck was a rope. Believing they had found evidence of a murder, the men called the police.

In pictures, the Tollund Man’s body appears startlingly fresh, with stubble on his chin and a violent expression on his face. His skin was so well preserved that investigators were later able to take a thumb print. He appears to be suffocating. But he isn’t: The man died more than 2,000 years ago, during Europe’s Iron Age.

Hundreds of bodies have been unearthed from bogs throughout Northern Europe. Some, like the Tollund Man, were initially assumed to be murder victims, and many were reburied in churchyards. The archaeology branch of the National Museum of Ireland in Dublin has four of the bodies on display in a group of glass exhibition cases, which allows visitors to peer at individual hairs and study desiccated hands with cleanly clipped nails. Your gaze reaches out across centuries.

The raised bogs of Northern Europe are ideal for preservation. The water in them is highly acidic and low in oxygen, which helps prevent decomposition. The tanning properties of bog moss do the rest. Clothing, tools and even blocks of bog butter have been dug out of the peat. When Danish scientists examined the Tollund Man, they discovered his final meal — gruel — in his large intestine.