Overview
Cheomseongdae stands in Gyeongju, the capital of the Silla kingdom, and was built during the reign of Queen Seondeok (632–647). It is generally regarded as an astronomical observation tower and is often called the oldest surviving astronomical observatory in East Asia.
Description
It is a bottle-shaped tower about 9.4 metres tall, built of roughly 360 cut granite blocks laid up around a square window. Interpreters have long read calendar symbolism into its construction — the courses of stones counted as the days of the year, for example — though these readings remain interpretation rather than established fact.
History and legacy
Exactly how the tower was used is still debated among scholars. It is designated a National Treasure of Korea and has become an emblem of Gyeongju’s Silla heritage.