Researchers estimate the mysterious woman, known as the Ukok princess, was probably 25 years old when she died nearly 2,500 years ago, ABC News reports. She was most likely a member of the Pazyryk tribe, nomads who lived in the Altai mountains of Siberia. Her mummy was discovered in 1993. It was kept preserved in the permafrost, which is why her tattoos are still visible.

“Compared to all tattoos found by archeologists around the world, those on the mummies of the Pazyryk people are the most complicated and the most beautiful,” Dr. Natalia Polosmak, the lead researcher, told The Siberian Times. “More ancient tattoos have been found, like the Ice Man found in the Alps - but he only had lines, not the perfect and highly artistic images one can see on the bodies of the Pazyryks. It is a phenomenal level of tattoo art. Incredible.”