In Xi'an, capital of northwestern Shaanxi Province, volunteers gathered at the night of March 27 to promote low-carbon activities in the north square of the Giant Wild Goose Pagoda, the city's 1400-year-old landmark Buddhist pagoda which goes dark during the "Earth Hour".

The "Earth Hour," initiated by the World Wild Fund for Nature (WWF) in 2007, calls on families and buildings to turn off the lights for one hour on the last Saturday night of March.

China has for the second year joined the annual global environment campaign.

Latest figures show that 33 Chinese cities will take part in the event along with more than 4,000 cities across the world.

In eastern Nanjing city, more than 400 buildings have taken part in the event, according to Liu Guoqiang, a local official in charge of city lighting.

"This time's event must be of larger scale than last year. Through these efforts, we hope every family could understand that now we've entered an era of low-carbon economy," said Liu.

"If we can use environmental-friendly products and turn off appliances which are not in use, it will create enormous benefits, " Liu added.

In Beijing, the Forbidden City will go dark for the "Earth Hour" for the first time, together with other world-famous landmarks like the Eiffel Tower in Paris and the Empire State Building in New York.

The buildings might be silent and still, but people have their own ways to spend the one dark hour of Saturday than merely turning off switches.

On the web page of a week-long poll on how to spend the 60 minutes when cities go dark, thousands of Chinese netizens contributed their own ideas. Many said they would go for a walk with friends and family and have a nice talk under the night sky free from floodlight pollution.

"I'll tell my daughter the stories about my childhood when I read books and did handiwork in the candle light. I'll tell her about the fish swimming in the creek near our house and that we could drink from any springs we found," wrote a netizen named Jin Yuxia.

In eastern Hangzhou, a one-hour "dark party" will be held to go with the campaign near the Leifeng Pagoda, the city's iconic tourist attraction located south of the West Lake.

"The reason for us to hold this activity is to tell people that without electricity, we can still enjoy life," Yang Dongwen, an official with the site's management department, told Xinhua.

About 80 students will take part in the unplugged party, playing Hulusi (a free-reed wind instrument) and joining ethnic bamboo pole dance.

According to the WWF official website, hundreds of millions of people from more than 100 countries are expected to take part in this year's "Earth Hour" campaign.