A special documentary series by KBS titled “23.5” has won the top prize for camera work at a Russian TV festival.

The first segment of the four-part documentary received the honor at the 25th International TV Ecological Festival on Friday hosted by the All-Russia State Television and Radio Broadcasting Company.

"23.5" refers to the number of degrees the Earth is tilted. The documentary looks at how this number allowed nature and civilization to blossom on Earth.

The program aired in March last year to mark the public broadcaster’s 47th anniversary.

The series took three years to produce at a cost of one-point-six billion won and was filmed in 15 countries. It was also screened at last year's Green Fest eco film festival in the best nature film category.