Since ancient times, the ancient people of Egypt and the Inca knew the art of tattooing, but it is almost impossible for us to see such works because they often disappear as the body decays. However, rare cases are still perfectly preserved after several millennia.
Here are some of the coolest tattoos ever found on ancient mummies.
Geometric tattoo on tzi the Iceman
A frozen man was found in a glacier in the Alps in 1991 with more than 60 tattoos painted 5,300 years ago.
The mummy is almost perfectly preserved, with skulls motorcycle most of her skin, clothing and hunting gear still intact.
Since its discovery, Ötzi the Iceman has been studied by many groups of scientists. Each time, they discovered new tattoos.
They arranged the tattoos into 19 different groups, each forming sets of horizontal and vertical lines.
Last year, experts suggested that tattooing could be a primitive form of acupuncture.
The tattoos often appear around Ötzi's joints and back, where there are signs of degeneration.
The Stone Age hunter was in his 40s or 50s when he died and used to travel tens of kilometers a day.

Lady of Cao's beast tattoos
A Moche woman who lived 1,600 years ago has spiders, snakes, catfish, crabs and even mythical beasts meticulously tattooed on her skin.
Known as the Lady of Cao, scientists found this mummy in El Brujo, Peru.
The woman's body was surrounded by gold ornaments and symbols of power leading scientists to believe that the Lady of Cao was of high status, most likely a priest.
Tattoos are made by applying charcoal color to the skin with a sharp needle or spine.
Lady of Cao died at the age of 20 (circa 450 AD) and dragon skull ruled a desert valley in Peru.
Her meticulously tattooed body was wrapped in 20 layers of cloth and buried with weapons and gold jewelry.
A bison tattoo on the Egyptian mummy Gebelein Man A
The world's oldest tattoos were found on the arm of a 5,000-year-old Egyptian mummy on display at the British Museum.
Gebelein A died when he was brutally stabbed in the neck between 3,341 and 3,017 BC.