Edinburgh Castle will be lit blue from dusk tomorrow to celebrate the United Nations' 70th anniversary.
Glowing sapphire above the city on Saturday, October 24, the castle will join landmarks such as the Empire State Building and the Leaning Tower of Pisa as part of a global initiative to turn the World UN Blue.
Beginning on Friday, some 250 sites around the world from Australia to Azerbaijan will be lit in 'UN blue' to mark the event.
The day marks the anniversary of the entry into force of the UN Charter.
Among the famous landmarks taking part in the ‘Turn the World UN Blue’ campaign will be the Great Pyramids of Giza in Egypt, the statue of Christ the Redeemer in Rio de Janeiro, the Great Wall of China, Russia’s Hermitage Museum and the ancient city of Petra in Jordan.
Culture, Europe and External Affairs Secretary Fiona Hyslop said: "Over the last 70 years the United Nations has protected and improved the lives of so many the world over.
"We want to congratulate the UN on its many achievements and help to promote its message of peace, development and human rights by lighting Edinburgh Castle blue.
"Many Scottish civil society organisations and individuals work hard to help the UN achieve its aims, often as unpaid volunteers. We want to thank them for this engagement and encourage more people to join their efforts."
Members of the public are being encouraged to share their pictures @UN #UNblue