The United Nations Day is being observed on Saturday, 24 October, and this year will mark 70 years since the United Nations was created to provide a forum for all countries to work out their problems peacefully.
To celebrate this important day, several iconic monuments and buildings across the globe will be lit up blue, to spread the message of international peace.
According to the UN website, several world famous landmarks such as Australia's Sydney Opera House, the Great Pyramids of Giza in Egypt, the statue of Christ the Redeemer in Rio de Janeiro and the Empire State Building in New York, will all be lit up in blue in a campaign called "Turn the World UN Blue" campaign.
Click here to see a list of all the landmarks that will turn blue on Saturday.
Here are a few quotes on the need for an organisation such as the United Nations.
More than ever before in human history, we share a common destiny. We can master it only if we face it together. And that is why we have the United Nations. â€• Kofi Annan
The UN is not just a product of do-gooders. It is harshly real. The day will come when men will see the U.N. and what it means clearly. Everything will be all right -- you know when? When people, just people, stop thinking of the United Nations as a weird Picasso abstraction, and see it as a drawing they made themselves - Dag HammarskjÃ¶ld
The whole basis of the United Nations is the right of all nations--great or small--to have weight, to have a vote, to be attended to, to be a part of the twentieth century - Adlai Stevenson
The United Nations is designed to make possible lasting freedom and independence for all its members - Harry S. Truman