A human head was found in a bag by a British woman out for a morning walk Wednesday.
The gruesome discovery was made in the Newhaven area of Edinburgh.
Lothian and Borders Police have launched an investigation.
It is thought the head may be several years old and it is not known how long it had been there.
Police said the head "appeared to be mummified."
It was found on a public footpath at Hawthornvale. The woman who found it raised the alarm at 1030 a.m.
A police spokesman said: "Obviously we are at the very early stages of this investigation, and at the moment we are trying to establish the identity of the deceased.
"At this stage it would appear that the remains are a number of years old, although it can't be said for certain how old they are until the necessary tests are carried out."
Officers are currently carrying out forensic examinations at the scene, and the area has been cordoned off while investigations take place.