Archaeologists clearing the coffins at Dingling Mausoleum. (Photo provided to China Daily)
The entire layout of the mausoleum is split in two－a rectangular part at the front and a circular part at the back, separated by a stone tower known as ming lou, or the Worldly Tower. The different shapes were meant to represent Earth and Heaven, believed by ancient Chinese to be in a square and a circle respectively.
The circular part, known as bao cheng, or the treasure city, has at its heart a big earth dune that rises to more than 10 meters above the ground. Since the burial chamber was most likely to be deep in the ground and directly under the peak of this symbolic burial mound, the question had always been: How to approach it?
The broken wall might be the place. And remember, this was in May 1956.
"The bricks had gone and there was a big hole about half a meter in diameter," Yang says. "Since it was three meters above the ground, the team members had to set up a human ladder to reach the hole and take a peek inside. It was a peek that would change the contemporary history of the Dingling Mausoleum."
The rim of the hole appears to its examiners like the upper edge of an arched gate. Peeking inside, the man at the top of the human ladder also glimpsed brick marks－marks left on earth indicating the previous existence of bricks. What according to some villagers had been a hiding place for local bandits reminded the archaeologists of the entrance to a secret tunnel.
Difficult quest
So they began digging. Two hours later, a stone stele was unearthed bearing the characters sui dao men, or tunnel gate. Ten days later, as the team arrived at 4.2 meters underground, they discovered brick walls on both sides of an 8-meter-wide path that ran along the circular wall of the Treasure City. In retrospect, the path, called "the brick tunnel" was the route the colossal coffins of the emperor and his two empresses traveled after their arrival at the mausoleum.
However, a promising beginning did not lead to a quick ending. After digging for months and finding nothing, the team jumped ahead and dug more along that same route, but still found nothing.
"It seemed that they had assiduously followed this clue that rolled out before them like thread from a skein, only to arrive at the end and find nothing but the end of the thread. It was in July and August, with rainwater constantly filling the trench. Yet just when most people were about to give up, the emperor, if you like, sent another beckoning."
The team unearthed a second stele. Inscribed on it was a line of words that translates as: "From here to the wall, the horizontal distance is 53.28 meters, and the vertical distance is 11.66 meters."
Today the stele, lying in a glass cabinet in one of the two exhibition halls of the mausoleum, is presented by tour guides to visitors as "the key of Dingling". And the wall mentioned is the one that separates the burial chambers of the emperor with the tunnel that leads to it.
"Elated by the new find, the team started digging its third and last tunnel from where the second stele was found, at the back of the Worldly Towers. Not long into digging, they discovered another tunnel－not a brick one but a much sturdier stone one that ran toward the center of the burial mound.
