Cheomseongdae

Cheomseongdae is an ancient astronomical observatory located in Gyeongju, South Korea. It was built in the 7th century during the Silla kingdom and is traditionally linked to Queen Seondeok, reflecting the era’s interest in astronomy and statecraft. It is widely regarded as the oldest surviving astronomical observatory in Asia and one of the oldest in East Asia.

The structure is a tall, slender tower made of roughly cut granite stones. It rises from a square base to a tapered, cylindrical form, forming a distinctive stony column that stands about nine meters high. The stones are arranged to create a stable vertical silhouette, and the upper portion forms a cap-like convergence. While precise historical details remain a matter of study, Cheomseongdae is understood to have served observational purposes related to celestial events and seasonal timing.

Cheomseongdae is designated as South Korea’s National Treasure No. 31 and remains a prominent cultural landmark in Gyeongju. It has undergone preservation efforts to protect its integrity while allowing public access, and it continues to be a focal point for discussions of early Korean science, architecture, and the Silla-era innovation in monumental astronomy.