SYDNEY (Australia) – The Sydney Opera House was one of the first buildings to light up the sky to celebrate the 70th anniversary of the United Nations and commemorate UN Day.

More than 300 monuments, landscapes, museums, bridges and other landmarks across more than 75 countries were lit up in the official colour of the United Nations.

The opera house is among many other of the landmarks and buildings lit up during the celebrations including the Great Pyramids in Egypt, the Empire State Building in New York, the Leaning Tower of Pisa in Italy and Westminster Hall in the United Kingdom.

“I am grateful our member states are showing such strong enthusiasm in marking 70 years of UN support for peace, development and human rights,” UN secretary-general Ban Ki-moon said.

“By turning the world UN Blue for a day, we can light the way to a better tomorrow.”

NSW Premier, Mike Baird, attended an event on Friday to mark the 70th anniversary of the United Nations at the Museum of Contemporary Art, Sydney. Top Australian actress, Cate Blanchett, also attended the event.

Royal Exhibition Building in Melbourne, lit up in blue for the 70th anniversary of the United Nations, September 23, 2015. Photo by UN (Stewart Donn)

Royal Exhibition Building in Melbourne, lit up in blue for the 70th anniversary of the United Nations, September 23, 2015. Photo by UN (Stewart Donn)

The Sydney Opera House was one of the first landmarks to be lit up for UN 70th anniversary. Photo: Dijana Damjanovic

The Sydney Opera House was one of the first landmarks to be lit up for UN 70th anniversary. Photo: Dijana Damjanovic