United Nations Secretary-General Ban Ki-moon poses for a photo in front of the United Nations headquarters lit in UN blue as part of the global celebrations of the 70th anniversary of the United Nations, in New York, the United States, Oct. 23, 2015. From the Sydney Opera House in Australia to the Great Pyramids of Giza in Egypt, more than 200 of the world's most iconic landmarks will be lit United Nations blue when the sun sets on Friday Oct. 24 to mark the 70th birthday of the global organization. (Xinhua/Li Muzi)
