Encrusted in dirt, and severely damaged by vermin and insects, it was destined for a skip after being discovered during a house renovation in Aberdeen - until a last-minute intervention.
What appeared to on first inspection to be "a bundle of rags" in fact turned out to be a rare 17th century map of the world - and one of only two in existence.
Now it has pride of place in the collection of the National Library of Scotland after being donated rolled up inside a plastic bag.
Experts at the library's Edinburgh headquarters were charged with one of its most complex ever conservation tasks to try to save the map, which was created by the celebrated Dutch engraver Gerald Valck, and measured seven foot by five foot.
Similar to a map featured in a famous work by the Dutch artist Johannes Vermeer, Painter In His Studio, it underwent five stages of treatment including opening and flattening the map, separating it out into its original eight sections, removing its linen backing, dry cleaning and washing, and re-assembling each cleaned section onto a new paper lining.
Each section of map was placed in a humidifying chamber to make it it easier to flatten them out, while the final stage of cleaning involved suspending them in water in a heated sink at 40C for 40 minutes.
Claire Thomson, book and paper conservator at the library, said: "nce the map was unfurled I was able to assess its condition, which I must admit filled me with dread.
"Much of the paper had been lost, and the remainder was hard and brittle in places and soft and thin in others.
"We needed to stabilise it to prevent any further deterioration, make it robust and easier to handle to get to a point where it could be studied by researchers.”
Dr John Scally, Scotland's national librarian, said: “This is one of the most challenging tasks our conservation team has faced and they have done a terrific job. Although significant sections of the map have been lost, the remainder has been cleaned and stabilised for future study and enjoyment.
"It would have been very easy for this map to end up at the bottom of a skip but thankfully it can now take its place among the magnificent maps held within our collection.”