Cheomseongdaeis an astronomical observatory in Gyeongju, South Korea. Cheomseongdae meansstar-gazing towerin Korean. Cheomseongdae is the oldest surviving observatory in East Asia, and one of the oldest scientific installations on Earth. It dates to the 7th century to the time of kingdom of Silla, which had its capital in Gyeongju. Cheomseongdae was designated as the country's...