Cristina Gallach, United Nations under-secretary-general for communications and public information, speaks to journalists during a press conference on the Global Event "Turns the World UN Blue" at the UN headquarters in New York, the United States, Oct. 19, 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 Oct. 24 to mark the 70th birthday of the global organization, the UN announced here Monday. (Xinhua/Li Muzi)
