The Shaanxi Provincial Institute of Archaeology said on Tuesday that seven ancient bridges were unearthed in the past two years at a site in Weiqiao, Xi'an, famous for its centuries-old relics, xinhuanet.com reported.

According to staff members of the institute, the bridges date back to between the late Warring States Period (475-221 BC) and the Tang Dynasty (AD 618-907).

One of the bridges, made of wood and featuring beam columns, was at least 15.4 meters wide and 880 meters long. It is the largest such bridge discovered anywhere.

In April 2012, the Weiqiao relics were discovered by local villagers on the south bank of Weihe River in Xi'an. Archaeological excavations are currently under way at the site.