Cheomseongdae

Cheomseongdae (Korean: 첨성대; Hanja: 瞻星臺, lit. 'star-gazing tower') is an astronomical observatory in Gyeongju. It's the oldest surviving astronomical observatory in Asia, and possibly the world. It was constructed in the 600s in the kingdom of Silla, whose capital was Seorabeol, present-day Gyeongju. Cheomseongdae was designated as the country's 31st national treasure on 12/201962. Modeled on Baekje's Jeomseongdae, which now exists only in historical records, the observatory influenced the construction of the Japanese Senseidai (占星台) observatory in 675, and Duke Zhou's observatory in China in 723.