Cheomseongdae Observatory

Basile Morin · CC BY-SA 4.0

East Asia's oldest surviving astronomical observatory, built in the 7th century from 362 stones.

Nine metres tall and shaped like a bottle, Cheomseongdae was raised around 634 under Queen Seondeok to observe the stars and set the farming calendar. Every number in it means something: 362 stones for the days of the lunar year, twelve courses below and twelve above for the months, and a window that divides the tower into two equal halves. It stands alone on the grass, ringed by flowers in summer and floodlit at night — the single most recognisable image of Gyeongju.

Visitor information

When is the best time to visit Cheomseongdae Observatory?

September–October

How much does it cost to visit Cheomseongdae Observatory?

Free

How long do you need at Cheomseongdae Observatory?

45 minutes

What are the opening hours of Cheomseongdae Observatory?

09:00–22:00, open year-round; it is floodlit after dark and worth a second visit at night

Did you know

Built around 634 under Queen Seondeok.
The oldest surviving astronomical observatory in East Asia.
Assembled from 362 granite stones and standing 9.17m tall.
National Treasure No. 31 of Korea.

Travel tips

Come at night to see it lit on the open lawn.
Flower fields bloom beside it in September–October.
Combine it with Daereungwon and Wolji Pond in one walking loop.

Source: https://www.gyeongju.go.kr/tour/page.do?mnu_uid=2378

Updated: 2026-08-05