If a comparison were to be made based on age and tilt, the 1,000-year-old structure on Tianmashan Mountain in Shanghai will definitely exceed the leaning tower of Pisa in Italy, according to a tourism official in Shanghai.
According to an article on China Daily, the octahedral tower was built in 1079 during the Northern Song Dynasty (960-1127). It has seven levels and is about 20 meters high. The building was originally used as a storage for Buddhist relics, and has survived a series of damaging events in the past that left only the brick tower remaining.
In 1982, the tower was found to be leaning to the southeast at an angle of 6.51 degrees. The top of the tower was displaced horizontally by 2.27 meters from where it would have been if the structure were perfectly vertical. A new survey, however, finds that it now leans at an even further angle of 7.10 degrees.
Ruan Yisan, a professor of urban planning at Tongji University, said that the tower, which has a history of nearly 1,000 years and serves as a cultural root of Shanghai, needs better protection.
Li Kongsan, an official at the cultural heritage bureau of Shanghai, said that that the tower's leaning is placed under control and that the city inspects the tower twice a year.
Li added that although the main body is not damaged, its exterior is deteriorating and has cracks. He said that repairs for the external walls of the tower will be conducted in the latter half of the year.
The Shanghai government has enlisted the tower as a cultural relic in 1983.
Experts said that the tower's tilt is caused by its foundations sitting on two different surfaces. One side of the tower is on the mountain's bedrock, while the other side is on stone ballast.