Case file · Cosmic event
Cheomseongdae, the star-gazing tower
A bottle-shaped stone tower built in Gyeongju under Queen Seondeok, often called the oldest surviving astronomical observatory in East Asia.
647 CE · 35.83, 129.22 · status: official
The account
Made of 362 cut stones, a number often linked to the days of the lunar year, the tower has a window halfway up. The Samguk yusa credits it to Seondeok's reign; it is National Treasure no. 31.
The sceptical view
Historians still debate whether it was a working observatory, a symbolic altar to heaven, or both.