Cheomseongdae Observatory

Cheomseongdae Observatory (瞻星臺) was a Silla astronomical observation tower for watching the movements of the heavenly bodies. In an age when the timing of farming was set by the movements of the sky and the fortunes of the kingdom were divined from observations, astronomy was a major concern of the state from early on. Cheomseongdae is thought to have been built against this background.

An old record says that "it is built so that a person climbs up through the middle". It seems people set a ladder against the outside, went in through the window, then climbed another ladder inside to the top to watch the sky. It is presumed to have been built in the reign of Queen Seondeok, and it was designated a National Treasure in 1962.

It is open all year, 09:00–22:00, and until 21:00 in winter. There is no admission fee.

By bus, take No. 10, get off at the Wolseong-dong Community Center stop and walk 5–7 minutes.

Gyeongju City directs drivers to the roadside parking at Cheonmachong Tomb and around Gyochon Hanok Village. The Jjoksaem temporary parking lot, reached via Wonhwa-ro 181beon-gil, is free.