We know pharaohs sent trading expeditions to a mysterious place they called the “Land of Punt” but until now we didn’t really know where that was. Thanks to oxygen isotope analysis and 3 baboon mummies in the British Museum, scientists think they’ve pinpointed the location of Punt: it was in an area that is now Eritrea and East Ethiopia.

Ancient Egyptians recorded travels to Punt where they got many exotic animals, including live baboons. There were no native Egyptian baboons, so we know the New Kingdom baboon mummies in the British Museum originated in the Land of Punt.

The team had permission to use baboon hairs from two of the mummies, and have just finished analyzing hairs from these baboons by using oxygen isotope analysis. Oxygen isotopes act as a ‘signal’ that can let scientists know where they came from.

It works this way because, depending on the environment an animal lived in, the ratio of different isotopes of oxygen will be different. “Oxygen tends to vary as a function of rainfall and the water composition of plants and seed,” said Professor Nathaniel Dominy of UC Santa Cruz, who is on the team.

The researchers compared the oxygen isotope values in the ancient baboons to those found in their modern day brethren.

“All of our specimens in Eritrea and a certain number of our specimens from Ethiopia – that are basically due west from Eritrea – those are good matches,” said Professor Dominy.

“We think Punt is a sort of circumscribed region that includes eastern Ethiopia and all of Eritrea.”

Some of the other possible Punt candidates — Somalia, Yemen and Mozambique — do not match the specimens.

The team can’t narrow the location down any further with oxygen isotope analysis, but one of the modern specimens from the Eritrean harbour city of Massawa is an excellent match for the mummy specimens.

The results came from a very limited sample, however, so grains of salt are necessary. Next up: strontium isotope tests on a pea-sized section of baboon bone. They don’t have the British Museum’s permission to take this larger sample yet, and there’s some export red tape to overcome.