Outside the Zhonghua Gate in Nanjing, Gao Song, the founder of Nanjing Urban Memory Folk Records Group, recently discovered several old manhole covers during the Republic of China. He said excitedly, "This may be the oldest manhole cover in China." Previously, several old manhole covers engraved with the words "Capital Telephone Bureau of the Ministry of Communications" had been found on Zhongshan North Road in Nanjing. The reporter interviewed experts in the history of the Republic of China, Nanjing Water Supply Corporation, Nanjing Telecommunications Bureau and other units and found that these old manhole covers should not be underestimated. They witnessed the first batch of Nanjing people who drank tap water and used telephones.

Gao Song took some photos of old manhole covers, and the traditional characters such as "Nanjing Waterworks" and "Engineering Bureau" were particularly eye-catching. In order to prevent too many tourists from damaging cultural relics, Gao Song has an extra mind: the specific address of the manhole cover has not been announced. In fact, these old manhole covers are located near the gate of a factory, and it is difficult for outsiders to notice what is special about them unless they are pointed out. Two of the three manhole covers are square, which is different from the common round manhole cover. One side of the manhole cover is engraved with three traditional characters of "Works Bureau", and the surface is covered with a staggered pattern of "two". The manhole cover has been polished because of its age. The other manhole cover belongs to "Nanjing Waterworks", but the words marked on it are traditional. The manhole cover is similar to the common round manhole cover, and the pattern is like a sunflower tray. Above the manhole cover, opposite the label of "Nanjing Waterworks", there are three characters of "Big Pipe Gate", which should indicate the purpose of this manhole cover.

Compared with the common manhole covers now, these three manhole covers are completely "oversized", at least one third larger. The surface of the manhole cover is a fishnet-like line, which looks simple and generous. There is a long small box in the center of the manhole cover, which is engraved with the words "Capital Telephone Office of the Ministry of Communications".

"All over the country, these manhole covers may be the oldest manhole covers." In March this year, Zhang He, an expert in architectural research of the Republic of China in Gulou District, Nanjing, and the director of the Cultural and Historical Committee jointly called for strengthening the protection of old manhole covers during the Republic of China. They are referring to the old manhole cover engraved with the words "Capital Telephone Bureau of the Ministry of Communications" on Zhongshan North Road.

Wang Xiaohua, an expert on the history of the Republic of China and a researcher at the Second Historical Archives of China in Nanjing, said, 1927 April, after the National Government made Nanjing the capital, it began to carry out urban construction, and the blueprint was the famous capital planning, in which the directors of functional zoning, traffic planning, municipal engineering and other projects were all foreign experts or high flyers who came back from abroad. "Nanjing Waterworks" and "Capital Telecommunication Bureau of Ministry of Communications" were established under this background.