Cheomseongdae Observatory, Gyeongju

Cheomseongdae is one of the must-visit places when visiting Gyeongju, a city of Silla cultural heritage.

Even if historical heritage is not considered, the wonderful night view of Cheomseongdae is enough to captivate travelers.

Cheomseongdae Observatory, Gyeongju

About Cheomseongdae Observatory

Cheomseongdae Observatory is thought to have been built during the reign of Queen Seondeok (r. 632-647) of the Silla Dynasty for observation of the movements of heavenly bodies.
It is the oldest astronomical observatory in Asia and is widely regarded as a precious cultural heritage that gives us a clear idea of the level of technological development of that time.

Standing approximately 9 m in height, this observatory consists of a cylindrical body, a platform, and a square top. The cylindrical body includes 27 layers of fan-shaped stones, and the outer face is trimmed smooth whereas the interior wall face is not even.
At the upper part, long ends of stone material that is geared into inside part of hash shape are extended to the outside.
This arrangement can be seen in layers 19-20 and 25-26, and so it is assumed that a ladder was easily placed easy on those steps in the inside.
Around the southeast opening, the lower part is filled with rubble, while the upper part to the top is open and hollow.
The eastern half of the uppermost step is blocked with a stone slab. It is presumed that there might have been some devices for observation inside the observatory.

The record of an ancient book states, “People can climb up through its middle.” It seems that one simply placed a ladder on its outside and climbed inside through a window, and then climbed up to the top via another ladder to observe the stars.
One researcher has suggested that the top might have been very convenient to sit, stand or lie on. During the ancient period, astronomy was deeply related to agriculture as farming times were often determined according to the movements of the stars.
It was also deeply related to politics in that the horoscope was considered to be important, since the good or bad fortune of a nation could be predicted according to the results of their observation of the stars.

Cultural Heritage Administraion
Cheomseongdae Observatory
Cheomseongdae Observatory, Gyeongju

The story of Cheomseongdae

The story that Cheomseongdae was used to see the stars has been gaining credibility.
However, it was pointed out that it was only 10m high from the ground and that the stars could be observed more easily when climbing the surrounding mountains, and the royal palace at a close distance was higher.
Therefore, it is argued that Cheomseongdae would have been a kind of monument, altar, or warehouse.

However, it is now said again that Cheomseongdae Observatory observed stars.
In that era, there were no tall buildings, so it was easy to see stars just as high as Cheomseongdae.
In other words, it was possible because there was no lighting at night like the present.

Finally, astronomy at this time is different from astronomy today.
At that time, the role of Cheomseongdae was not to observe stars for scientific research, but to predict the national fortune.

The most important point of Cheomseongdae is that stars were observed in this era.


Cheomseongdae is near Hwangridan-gil, which is the most popular among young people in Gyeongju, so it is good to visit Hwangridan-gil and look around together.

The night view of Cheomseongdae Observatory and the night view of Donggung Palace and Wolji Pond are essential courses for Gyeongju travel.
I hope you visit both places at night.

Address : 140-25, Cheomseong-ro, Gyeongju-si, Gyeongsangbuk-do

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