"The Beijing Central Axis is not only a cluster of separate buildings," explains Deng Chao, director of the department of historic monuments under the National Cultural Heritage Administration.

"The roads and bridges along the axis connect the heritage components and form a continuous entity."

However, compared with many magnificent architectural structures rising along the northern section of the axis, the southern section needs to be better clarified in the public's eyes as it has a smaller number of grand buildings, as Deng notes.

Archaeology thus plays a crucial role in helping people to understand the values of this section.

On the Zhengyang Bridge site and other spots along the southern section of the Central Axis, Zhang's team has been devoted to unveiling some crucial but long-forgotten chapters of the past.

In the Zhushikou area near the southern end of Qianmen Street, archaeologists found drainage ditches of the Qing Dynasty, the style of which is identical to those of royal resorts of that time.

Remains of the Tianqiao Bridge, which is more than 1 kilometer to the south of Zhengyang Bridge, were also discovered.

Thanks to the archaeological work, the southern section road, which was the route used for national rituals and ceremonies during the Ming and Qing dynasties, was gradually resurrected.

Zhang's team found as many as seven layers of overlapped road foundations. She says that the deepest layer may date back to the Yuan Dynasty (1271-1368) or earlier, when the Central Axis was first formed, but she adds more evidence awaits to be unearthed.

The Southern Section Road Archaeological Sites were listed as one of 15 components gaining World Heritage status as part of the "Beijing Central Axis: A Building Ensemble Exhibiting the Ideal Order of the Chinese Capital".

As the World Heritage bidding documents point out: " (The sites) are material evidence that irrefutably show the location, orientation, engineering techniques and history of the continuous use of the central road and bear witness to the state ritual traditions that have continued on the Beijing Central Axis to this day."

Jiang Bo, vice-president of the Chinese national committee for the International Council on Monuments and Sites, says: "Since the initiation of the World Heritage application project, Beijing residents have revitalized their memories and devoted themselves wholeheartedly to the protection of urban cultural heritage with unprecedented enthusiasm.

"The ancient city is returning in a new heritage landscape."

wangkaihao@chinadaily.com.cn