The **Danyang-Kunshan viaduct** is a massive elevated rail structure that stretches 164.8 kilometers, making it the longest of its kind in the world. It supports the **Beijing-Shanghai high-speed rail line**, which connects two of China's largest cities. Completed in 2010 and officially opened on June 30, 2011, the viaduct cost an estimated 8.5 billion dollars. This figure, based on a secondary source, amounts to roughly 52 million dollars per kilometer. The structure runs through several cities in Jiangsu province, including Danyang, Changzhou, Wuxi, and Suzhou, which lie along the route between Nanjing and Shanghai. The **Danyang-Kunshan viaduct** is not a traditional bridge over a river but an elevated rail track crossing the flat landscape of the Yangtze River delta. It passes over villages, canals, rice fields, and lakes, with 9 kilometers of track spanning over Lake Yangcheng. The structure averages about 30 meters in height, similar to a 10-story building. Technical descriptions from specialized websites note that the viaduct was built to avoid disrupting the local environment and allow the high-speed rail to travel unimpeded. The **Guinness World Records** recognized the **Danyang-Kunshan viaduct** as the world's longest bridge in 2011, rounding the length to 164 kilometers (102 miles). Meanwhile, **Wikipedia** provides the more precise figure of 164.8 kilometers, which is also the standard in technical documentation. The viaduct holds this title alongside other parts of the **Beijing-Shanghai high-speed rail line**, which includes the **Tianjin viaduct** (113.7 km) and the **Cangde viaduct** (about 105.9 km), both also completed in 2010. These three structures are among the six longest in the world and are all part of the same high-speed rail corridor. Travel time between Beijing and Shanghai has reportedly been cut in half, from about 10 hours to around five, according to a secondary source. However, this figure should be considered an estimate. The **Danyang-Kunshan viaduct** specifically connects the cities of Danyang and Kunshan, and while it is part of the larger **Beijing-Shanghai** line, not every section of the route follows the same elevated structure. The 164.8 km section in Jiangsu province is the one that holds the record, highlighting the engineering scale and ambition behind China's high-speed rail network.