The world's most famous landmarks are plunged into darkness for one hour every year.

The global Earth Hour campaign raises awareness about the impacts of climate change. It started in Australia in 2007 and is now observed by participants in 187 countries, according to organisers.

Here are some major sites across the globe that dimmed their lights on Saturday 24 March 2018.

Sydney, Australia - Harbour Bridge and Opera House

Image copyright AFP

Image copyright AFP

Beijing, China - National Stadium (the "Bird's Nest")

Image copyright EPA

Image copyright EPA

Kuala Lumpur, Malaysia - Petronas Towers

Image copyright EPA

Image copyright EPA

Taipei, Taiwan - Taipei 101

Image copyright EPA

Image copyright EPA

Singapore - Supertrees at Gardens by the Bay

Image copyright Reuters

Image copyright Reuters

New Delhi, India - India Gate

Image copyright AFP/Getty

Image copyright AFP/Getty

Moscow, Russia - Christ the Saviour Cathedral

Image copyright EPA

Image copyright EPA

Minsk, Belarus - The Bolshoi Opera and Ballet Theater

Image copyright EPA

Image copyright EPA

Rome, Italy - Colosseum

Image copyright AFP/Getty

Image copyright AFP/Getty

Athens, Greece - Parthenon temple

Image copyright Reuters

Image copyright Reuters

Photos are copyright.