On the afternoon of Dec 23, over 500 street cleaners were invited to a mutton soup restaurant in Southwest China's Chongqing city to celebrate the Winter Solstice, the 22nd solar term of the year.

Enjoying mutton soup is a local tradition in Chongqing on this special day. To show his gratitude and respect to the workers, Zhang Shiwen, the restaurant owner, has been treating them with a hot lunch for free for 17 years.

"This started in 2002 when I was a street vendor in downtown Jiefangbei," he said. "Street cleaners work very hard to keep our city tidy, but many people still look down upon them. So I decided to do something to show my respect."

At the beginning, his guests were not many. Since Wang opened a restaurant in 2010, thousands of street cleaners have become his guests.

This year, the restaurant in Shapingba district prepared 250 kilograms mutton for the lunch.

"I will continue this free lunch project as long as I can," Zhang said.