BEIJING - Beijing began its largest renovation project on a section of the Great Wall to date in the city's northern Huairou district on Wednesday.

With a budget of 41.8 million yuan ($6.5 million), the unprecedented renovation work will stretch along 3,553 meters and encompass 25 watchtowers of the Great Wall in Hefangkou village, Huaibei township.

The project aims to prevent collapse around some loose parts of the Great Wall, as well as to remove potentially dangerous problems with and strengthen the main body of the structure, according to the municipal cultural relics bureau.

The renovation project is expected to be completed by 2012. It has been listed in Beijing's mid- and long-term plan for cultural relics renovation in 2011.

Historical records indicate that the Hefangkou section of the Great Wall was a place of great military importance since it was built in the Ming Dynasty (1368-1644).

The meticulously-built section has been damaged due to a lack of maintenance over the years.