The bog bodies of Northern Europe are a large set of human cadavers that have been naturally mummified within the peat bogs found on the continent. They have a widespread chronology spanning from 9000BC to World War 2.
What’s really different about the bog bodies is that their skin and internal organs have been preserved extremely well due to the condition that they’re in: The water is highly acidic, temperature is low and there’s no oxygen. This combines to preserve, but tan their skin.
The other interesting thing, though is that the bog bodies’ bones are generally not preserved. The peat dissolved the calcium phosphate of the bone. If you want to learn more about these corpses, check out the source!