A symbolic key made by architect Charles Rennie Mackintosh for the 1899 opening ceremony of the Glasgow School of Art - a building he designed - is selling in Edinburgh.
The piece is valued at up to £30,000 ($41,538).
Incredibly, this is the first time the key has been seen in public since the opening, nearly 120 years ago.
The key is still in its presentation case
Mackintosh designed the key himself. It’s very much in the arts and crafts style of the building.
The project made Mackintosh one of the most sought after names in architecture. However, he would become tired of his work and spend much of the rest of his life painting intricate watercolours.
John Mackie, director of Lyon & Turnbull - the auction house handling the sale, said: “This is a remarkable object.
“As an architect and designer, Mackintosh is seen as a major transitional figure from the historicism of the 19th century to the abstraction of the 20th century.
“His masterwork, the new Glasgow School of Art of 1899 and 1910, became a building that has come to symbolise his achievement as an architect.”
A portion of the money raised from the sale will go to the Mackintosh Campus Appeal.
This will ensure the survival of the building, which was badly damaged by a fire in 2014.
The sale will take place on April 11.
You can check out all our art and photography memorabilia for sale here.
Please sign up to our free newsletter to receive exciting news about unique item auctions.