Hongze Lake Ancient Dike (Gaojiayan)

The Hongze Lake Ancient Dike (洪泽湖古堰), also known as the Gaojiayan dike, is located at 1 Xunhe West Road in Hongze District, Huai'an, Jiangsu province. It forms part of a long embankment on the eastern shore of Hongze Lake, one of China's largest freshwater lakes, and was constructed to contain the Huai River waters that threatened the Grand Canal and the plains to the east. The origins of the dike are traditionally traced to the Eastern Han dynasty, but the structure seen today is mainly the product of the Ming and Qing dynasties, when engineers raised, lengthened and faced the earthen embankment with stone to withstand floods. During the Qing period the dike was reinforced with granite blocks laid in courses and bound with iron clamps and sticky rice mortar, an advanced technique of the time. The dike, stretching for tens of kilometres, protected agricultural land and the canal trade that supported the Qing economy, and its upkeep was a matter of national concern. Sections preserved for visitors include stone retaining walls, water gates and sluices, and monuments commemorating the engineers and officials who managed the works. Information displays explain the dike's construction, the dynastic policy known as storing clear water to flush the Yellow River silt, and the lake's changing level. Visitors can walk along the stone embankment with views over the broad lake, and boat trips are sometimes available. The scenic area is open from 08:30 to 17:30, and admission starts at about ¥50. Hongze District is some distance from the city centre, so most visitors reach the site by car or bus, and should allow about two hours for the dike and surrounding lakeside exhibits.