In pictures: Lights go out for Earth Hour

People celebrated Earth Hour by lighting lanterns in Berlin, Germany.

Famous landmarks around the world have turned off their lights for Earth Hour.

Earth Hour is an hour every year where people are encouraged to turn off their lights, to raise awareness of environmental issues.

In the UK the Houses of Parliament and Big Ben in London went dark on Saturday evening.

Landmarks like the Sydney Opera House in Australia and the Eiffel Tower in France also turned off their lights.

More than 350 landmarks in 178 countries took part in the event - here are some pictures of them before and during Earth Hour.

Big Ben in London, England is usually brightly lit up all night.

But it went completely dark for Earth Hour on Saturday evening.

The Eiffel Tower in Paris is a worldwide symbol of France.

It turned off its lights for Earth hour and plunged Paris into darkness.

This Gothic cathedral in Cologne is one of Germany's most famous landmarks.

When it went dark for Earth Hour, it was almost impossible to see it against the night sky.

The world famous Sydney Opera House in Australia is usually brightly lit up.

The Opera House turned off all its lights to mark Earth Hour.