Yichun Drum Tower

Yichun Drum Tower

Drum Tower — China’s Oldest Existing Local Astronomical Observatory

The Drum Tower, also known as Yuanzhou Qiao Lou. According to the Yuanzhou Prefecture Records, the Drum Tower was built in the second year of Baoda during the Southern Tang Dynasty by Prefect Liu Renzan, with records stating “hallways, study chambers, and the Qiao Lou...

...totaling six hundred rooms.” Later, in the twelfth year of Jiading during the Southern Song Dynasty (1219 AD), the Prefect of Yuanzhou, Teng Qiangshu, “renovated the Qiao Lou” and crafted instruments such as an hourglass, water clock arrows, a gnomon, a water basin, a south-pointing needle, timekeeping tally sticks, and iron plates. He established a system where yin-yang scholars took turns on duty, using these tools to report the time, thus transforming it into a full-fledged astronomical observatory capable of time measurement, timekeeping, and time announcement.

It wasn’t until the 1990s that the Drum Tower was confirmed as the oldest existing local astronomical observatory site in China. On September 20, 1991, Mr. Bo Shuren, a researcher at the Institute of Natural Science of the Chinese Academy of Sciences and an expert in ancient astronomical history, visited Yichun for an investigation. To his surprise, he discovered that the history of the Drum Tower actually predates both the previously recognized oldest local astronomical observatory site in China — the Dengfeng Ancient Astronomical Observatory in Henan (built around the early Yuan Dynasty, late 13th century) — and the oldest one abroad — the astronomical observatory in Uzbekistan (established in the early 15th century).

In September 1994, the Jiangxi Provincial Science and Technology Commission organized a committee of eight experts and scholars from Beijing, Nanjing, and the province to conduct an investigation and evaluation of the Yichun Drum Tower. They confirmed that “the Yuanzhou Qiao Lou, created in the twelfth year of Jiading during the Southern Song Dynasty, is the oldest existing local astronomical observatory site in China.”

The Yichun Drum Tower mainly used instruments such as the “copper clepsydra” to keep, announce, and measure time, with its timekeeping differing by only 20 seconds per day compared to modern clocks. During the Ming Dynasty’s Wanli era, a bronze armillary sphere was cast on the tower’s observation platform to enhance celestial observation capabilities.

Built during the Southern Song Dynasty, the Yichun Drum Tower is the oldest existing local astronomical observatory in the world, shining brightly in both Chinese and global astronomical history.

Preserved for nearly a thousand years to this day, the Yichun Drum Tower is located in the middle section of Drum Tower Road. Constructed in the twelfth year of Jiading during the Southern Song Dynasty (1219 AD) under the organization of Yuanzhou Prefect Teng Qiangshu, the Drum Tower also served as a watchtower for the prefectural government to observe celestial phenomena and announce timekeeping, hence also known as Yuanzhou Qiao Lou.

The building is a high-platform structure with an arched passageway spanning the north-south street, rectangular in shape, oriented east-west, with a hip-and-gable roof, double eaves, glazed tiles, plain tile ends, post-and-lintel wooden framework, four pillars per bay, five bays in width, three bays in depth. It stands 12.8 meters tall, 11.8 meters wide, 23.8 meters long north to south, covering an area of about 780 square meters. The street-spanning arch is 4.3 meters wide with an interior height of 5.6 meters. The eastern and western arches bear inscribed stone plaques reading “Drum Tower” and “Remaining Glow” in intaglio regular script. At both the northern and southern ends of the tower are observation platforms measuring 19.5 meters long and 7.6 meters wide.

The upper floor houses instruments such as a copper clepsydra, night water tank, day water tank, leveling tank, universal water tank, water basin, gnomon, south-pointing needle, water replenishment bucket, timekeeping tally arrows, and iron plate drums. It also “assigned yin-yang scholars to take turns, using tally sticks to announce the time.” Later, a bronze armillary sphere — an ancient celestial observation device developed by the famous Tang Dynasty Taoist Yuan Tiangang — was also added.

To determine the historical role and scientific value of the Yuanzhou Qiao Lou, the Jiangxi Provincial Science Committee designated it as a key research project in the early 1990s, inviting over 20 renowned experts and professors from institutions such as the Institute for the History of Natural Sciences of the Chinese Academy of Sciences, the Astronomy Department of Nanjing University, the Beijing Planetarium, the Purple Mountain Observatory in Nanjing, and the Architecture Department of Tsinghua University to hold an appraisal meeting. The scholars unanimously concluded that the Yuanzhou Qiao Lou is the oldest existing local astronomical observatory in China dedicated to timekeeping, integrating time measurement, timekeeping, and time announcement. It predates the astronomical observatories built by the Timurid Empire (now in Uzbekistan) by two centuries and the Gaocheng Astronomical Observatory in Dengfeng, Henan, built in 1276 AD, by over fifty years. Notably, the 24 main pillars of the tower, each made from large, embracing timbers, lean toward each other — the eastern eight and middle eight leaning east, and the western eight leaning west — yet the rooftop remains level and has not tilted for nearly 800 years, demonstrating the extraordinary architectural craftsmanship of its time.

Prominent experts in Chinese astronomy and architecture wrote solemnly in the appraisal report titled “Yuanzhou Qiao Lou — Research on China’s Oldest Existing Local Timekeeping Astronomical Observatory”: “Looking at the world today, apart from the Chinese cultural system, no other country has been found to have built a timekeeping astronomical observatory earlier than the Yuanzhou Qiao Lou. Therefore, its discovery will have a profound impact on astronomical research in both China and the world.”

The Yichun Drum Tower has undergone multiple renovations over the years to preserve its unique charm. It was renovated during the Ming Dynasty’s Jiajing and Wanli eras, with a plaque reading: Yingxi Tower. During the Qing Dynasty’s Kangxi and Qianlong eras, the western part of the tower was renovated, and a new plaque was hung reading: Remaining Glow. The last renovation occurred during the Tongzhi era of the Qing Dynasty. After the founding of the People’s Republic of China, the Party and government placed great importance on protecting this valuable cultural heritage. In 1983 and 1984, provincial cultural authorities allocated special funds to restore the tower to its original state and opened it to visitors. In December 1985, the provincial government approved its designation as a provincial-level scenic spot.

After comprehensive restoration, the Yichun Drum Tower, restored to its Ming and Qing architectural styles, along with an astronomy-themed square embodying distinctive features of Yichun, will soon be officially opened to the public. Its classical charm and modern vibe, traditional aesthetics and open spirit, blend harmoniously, continuing the deep cultural legacy of Yichun.