File photo of the Great Wall.

China launched a project Wednesday to restore the oldest part of the Great Wall, a stretch in eastern Shandong Province.

The first phase of the project covers 18 sections of the "Great Wall of Qi" with a total length of 61 km. It will cost 208 million yuan (34 million U.S. dollars), according to Xie Zhixiu, head of the provincial cultural heritage administration.

Shandong will also launch projects this year to protect the natural environment and ancient military facilities along the Wall, said Xie.

Built between 770 BC and 476 BC in the ancient state of Qi, today's Shandong, the Great Wall of Qi started at a small village in what is now Changqing District of Jinan City, with passes, gates, castles and beacon towers along a total length of 641 km till it met the sea near Qingdao.

Due to natural erosion, construction, mining and land reclamation, the Great Wall of Qi is in a worsening condition.

As military defense projects, more than 20 emperors in ancient China ordered the building or renovation of walls and fortifications. The Great Wall of China was made a World Heritage Site in 1987.