As the only mausoleum in Chinese history that contains both an emperor and a reigning empress, and the only tomb that has not been robbed in its more than 1,000 years of existence, Qianling Tomb has drawn the attention of archaeologists and lay people alike, but the debate over whether to dig on the site still sees much disagreement.

As one of the 18 emperors' tombs of the Tang Dynasty (618-907) peppered throughout central Shaanxi Province, Qianling Tomb's uniqueness lies in the fact that it houses the remains of Emperor Gaozong (628-683), the dynasty's third emperor, and his wife Wu Zetian, who ascended to the throne seven years after her husband died. She is the only empress in Chinese history.

Construction of the tomb, which sits inside Liangshan Mountain, located about 70 kilometers northwest of Xi'an, the provincial capital, began in 684 and finished 23 years later.

The door of Qianling Tomb was accidentally discovered in 1958 by local farmers who were using explosives to harvest stones for the rebuilding of a road.

The monument is also unique in that the queen's tombstone is completely devoid of written words, a choice that was made to reflect that the empress' achievements were too great to describe. Sixty-one headless statues of foreign officials stand at the foot of the mountain, guarding the tomb.

Technical difficulties

Despite its allure, the tomb has lain unexplored since the farmers' discovery.

"The current technology we have is not adequate and we don't have the confidence to guarantee the preservation of the relics once the tomb is opened," said Liu Qingzhu, former director of the Archaeology Institute of the Chinese Academy of Social Sciences.

Liu says many aspects of the tomb's interior remain unknown, such as its temperature, humidity and air composition.

"Even if we dig a tiny hole, outside air will inevitably enter the tomb, immediately changing the relics' environment. This is harmful to artifacts that have been used to the invariable environment that has preserved them for such a long time," said Liu.

Shen Ruiwen, an archaeology professor at Peking University, also opposes excavating the site, saying that some relics break into pieces immediately once they are exposed to the outside environment. He has studied the tombs of the Tang Dynasty for over a decade.

According to Shen, the design of Tang Dynasty tombs was inspired by that of the then capital Chang'an (now Xi'an). Qianling Tomb marks the beginning of the tradition of burying Tang emperors inside the mountains of central Shaanxi Province.

In explaining his misgivings about possible plans to dig, Shen referred to Dingling Tomb from the Ming Dynasty (1368 - 1644), located in the outskirts of Beijing, whose excavation is considered a failure in the eyes of most archaeologists.

"We will dig only when the technology is ready," said Shen.

"There are still many protection measures to consider for the above-ground relics from the Tang Dynasty, let alone underground ones," said Liu Xiangyang, deputy curator of Qianling Mausoleum, where he has worked for over 25 years.

The tombs of the Tang Dynasty typically cover a large area of land, with stone statues of people, lions, horses and birds surrounding the burial site.

Shi Xingbang, a 90-year-old archaeologist at the Archaeological Institute of Shaanxi Province, is one of the few who are in favor of digging in the tomb.

As a master of the field who played a leading role in digging the underground palace of Famen Temple in Shaanxi Province and participated in the digging of Dingling Tomb and other important projects, Shi says the preparations to excavate Qianling Tomb began soon after it was discovered, and that technology has been developed over the years.

Shi says while the tomb is being dug, advanced machines can record every element of the air inside and then recreate it in an artificial environment.

"Putting the relics in an environment that is exactly like the original is the most important thing," said Shi, explaining that man-made conditions can preserve most relics, though some are likely to have already corroded underground. He argued that technical issues are not what has held back exploration of the tomb.

A history of red tape

After Dingling was excavated in the 1950s, policies relating to such projects became tougher, and any proposal to dig at tomb sites had to be approved by the central government.

Qianling Tomb was in fact approved for digging early on, but plans were delayed after the unsuccessful excavation of Dingling and two other tombs, and an additional five years of research and planning were scheduled before ground could be broken on the site.

"Then the Cultural Revolution (1966-76) began, which of course stopped any plans to explore the tomb," Shi said regretfully.

According to the archaeologist, two huge projects were proposed in the 1990s: the building of the Huangdi Mausoleum (located in Huangling county, Shaanxi Province) and an excavation of Qianling Tomb. The former has been realized while the latter not, due to differing opinions among scholars, which in turn affected top leaders' decisions.

Concerns for posterity

"Our generation cannot use our ancestors' heritage to make money," Liu told the Global Times.

He further asserted that it is better for the relics to remain underground, in case of war or geological disasters that could harm them.

"Just as tombs of common people are the roots of families, emperors' tombs are the roots of a nation as national cultural relics, and their contents should remain intact forever," said Liu.

He added that he cannot think of any good reason to dig Qianling Tomb, explaining that such efforts should be permitted for the discovery of the unknown world, but not to satisfy personal hobbies or curiosity.

Liu says emperors' tombs are the carriers of ancient cultural materials that still have a connection with today's world, and they are the best objects of research we have. They also contain nonrenewable resources, which is why relics are valued at such a high price.

"Nothing lasts forever, but trying our best to prolong the life of cultural relics is our mission," said curator Liu, adding that we should be vigilant in our role as guardians of culture so that future generations may benefit from their preservation.

However, in archaeologist Shi's opinion, those who are against excavating the tomb are overly conservative when it comes to the protection of relics. He thinks these artifacts should be unearthed so that their historical value can be known to the world, adding that it is a waste to leave those valuable things untouched forever.

 "With the 61 statues of foreign officials showing their submission and respect to the great Tang Empire, the tomb would definitely bring unexpected benefits to today's China if excavated," Shi told the Global Times in his small office filled with old books.

Elusive crypt

Tomb raiders tried to locate the door of this Tang Dynasy tomb for over 1,000 years, to no avail. In its history, the tomb has escaped 17 documented attempts of large-scale robbery.

More than 20 years before the collapse of the Tang Dynasty, 400,000 soldiers were mobilized by warlord Huang Chao, and a 40-meter ditch was dug, gauging out half of the mountain, but the door remained undiscovered.

After the collapse of the Tang Dynasty, another warlord, Wen Tao, excavated over 10 Tang emperors' tombs, and he is believed to have brought catastrophic destruction to many ancient tombs. He too ordered the looting of Qianling Tomb, commissioning tens of thousands of soldiers to dig on the mountain, but was spooked by stormy weather and halted operations.

The most recent attempt to rob the treasures at Qianling occurred a century ago, by another warlord named Sun Lianzhong, but of course, he also met with failure.

Perhaps motivating the persistent, unsuccessful tomb raiders was the rumor that the original manuscript of Lanting Xu, one of the most well-known works of calligrapher Wang Xizhi, accompanied Wu Zetian in her final resting place.

According to historical documents, Emperor Taizong, Gaozong's father, loved calligraphy so much that he ordered Lanting Xu to be placed under his pillow when he was buried. However, the work was reportedly not found with Taizong when his tomb was looted years after.

The time when Gaozong and Wu Zetian were in power was the most prosperous period of the Tang Dynasty. Scholars believe that inside this tomb, extraordinarily valuable relics have been sealed up for over a millennium.

But curator Liu refutes the claim that 500 tons of relics are inside the underground palace, because relics have always been counted in groups or pieces, not in weight.

"It must be clarified that Wu Zetian was buried in the tomb with her emperor husband as a wife and queen, not an empress," said Shen.

Shen proposed that the value of Qianling Tomb may have been inflated because of the large number of artifacts throughout the surrounding grounds. He told the Global Times that he believes that the wisdom in the overall layout of the tomb still resonates today.