Her skin had been tanned in the dark tea of the bog.

 Yde Girl and Tollund Man are a reminder that humans once had very different and more respectful relationships with the bog, she said: “Bog bodies — and artifacts and eco-facts — become strange kinds of ambassadors from deep time. They re-enchant us with these landscapes through their stories.”

https://www.nytimes.com/2023/01/30/science/archaeology-bogs-mummies.html