Cheomseongdae Observatory

Gyeongju, North Gyeongsang Province, South Korea

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Cheomseongdae Observatory in Gyeongju, South Korea, is one of the oldest surviving astronomical observatories in the world, built during the 7th century under Queen Seondeok of the Silla Kingdom. Standing about 9 meters tall, the observatory is made of 365 granite stones, symbolizing the days of the year, and features a unique cylindrical shape with a square window halfway up.

Its design reflects advanced scientific knowledge for its time and served to help ancient astronomers observe stars and planets, aiding farmers in predicting seasons for planting and harvesting. The structure is not only a scientific tool but also a symbol of Queen Seondeok’s power and vision, with many elements of the design representing lunar months, solar terms, and other astronomical cycles.

Cheomseongdae has remained largely unchanged for more than 1,300 years and is now a UNESCO World Heritage Site, representing both Korea’s rich history and its early achievements in astronomy. It attracts many visitors interested in the cultural and historical significance of this ancient landmark.