In Beijing, the iconic "Bird's Nest" National Stadium and "Water Cube," the most prominent 2008 Olympic venues usually illuminated by floodlights, went dark at 8:30 p.m., while dozens of hotels, office buildings, shopping malls and restaurants in the capital also switched some lights off.

The iconic "Bird's Nest" National Stadium and "Water Cube", the most prominent 2008 Olympic venues usually illuminated by floodlights, went dark in Beijing at 8:30 p.m., March 28, 2009. [People's Daily]

A combination picture shows China's National Aquatics Center "Water Cube" in Beijng before and after the lights were turned off for Earth Hour March 28, 2009. About 20 Chinese cities joined a worldwide campaign to persuade the public to switch off unnecessary lights for one hour Saturday night to support energy-saving efforts and show concerns about global warming. [Gong Lei/Xinhua]

From residents of the north Indian city of Shimla to south India's small organization called the Kerela Sahitya Parishad, support for turning off the lights has been tremendous. At least 200,000 students from New Delhi and Mumbai alone have pledged their support, according to a WWF statement.

In the Giza plateau in the western suburb of Cairo, the colorful lights on the giant Pyramids and Sphinx disappeared exactly at 8:30 p.m. local time.

Besides the Pyramids and Sphinx, Bibliotheca Alexandria and sound and light shows in the southern Egyptian tourist cities of Luxor, Aswan and Abu Simbel also joined the event. "It is a pleasure to be part of the global event." Maged el-Deeb, general manager for marketing of the Misr Sound and Light Company, told Xinhua.

In South Africa, Table Mountain was to be seen only by starlight for an hour.

In London, the lights went off at the Houses of Parliament and the electronic billboard at Piccadilly Circus.

This combo photo taken on March 28, 2009 shows the Greater London Authority (GLA) building after its lights are turned off (bottom) and lit up again, in London. Landmarks in London including the GLA building, the parliament building, the London Bridge and the Big Ben turned off their lights for one hour from 8:30 p.m. to celebrate the Earth Hour, a worldwide movement to show commitment towards slowing the effect of global warming. [Zhang Liqing/Xinhua]