14/05/2026
Cheomseongdae (Korean: 첨μ±λ; Hanja: η»ζθΊ; lit. 'star-gazing tower') is an astronomical observatory in Gyeongju, South Korea. Cheomseongdae is the oldest surviving astronomical observatory in Asia,[1][2][3] and possibly even the world.[4][5][6] It was constructed during the Silla period, during the reign of Queen Seondeok (r. 632β647 AD).[7] Cheomseongdae was designated as the country's 31st national treasure on December 20, 1962.[8] It is part of Gyeongju Historic Areas, a UNESCO World Heritage Site.[9]
Cheomseongdae is mentioned in the popular Korean drama Queen Seondeok. In the 2009 drama, Cheomseongdae was constructed when Queen Seondeok was still a princess; this was her first decree as a princess. Cheomseongdae was meant to share the knowledge of astronomy with everyone, rather than letting one person (Lady Misil) abuse the knowledge of it. By doing so, she also abdicated her divine rights. Because this was uncommon at the time and unsupported by many conservatives, at the opening of Cheomseongdae, barely any nobles showed up.
The number and placement of the stones in Cheomseongdae have been theorized to represent various historical and astronomical figures.
The central hole or window separates the body into 12 layers of stones both above and below, symbolizing the 12 months in a year and the 24 solar terms. Additionally, the 12 stones which comprise the stylobate may also reference the 12 months.
