TIANJIN -?The renovation of 19 iron cannons has begun in north China's municipality of Tianjin.

The cannons were part of the Dagukou Battery, built in 1816 on the estuary of Haihe River, an important battlefield during the Second Opium War from 1856 to 1860.

The work is scheduled to take a year, said Ma Wenyan, curator of the Dagukou Fort Ruins Museum.

She told Xinhua that the cannons will be thoroughly cleaned to remove all rust and sealed to prevent further corrosion.

"The project will set the standard for the renovation of iron antiques in China," Ma said.

The Second Opium War was between China and, Britain and France. Chinese general Le Shan fought at Dagukou and died in the war in 1860.

When Anglo-French forces finally occupied Beijing, they looted and sacked the Old Summer Palace.