Korea honors a long-standing legacy of astronomy, treasured for thousands of years. The origin of Korean ancient astronomy dates back to the prehistoric era. Astronomical signs in the prehistoric age are star-like cup-marks carved on cover stones of dolmens. It is evident that ancient Korean kingdoms established own bureaus of astronomy, built observatories, and employed administrators designated to observe astronomical phenomena. Initial observations of astronomical phenomena started from the 1st century BCE and over 20,000 extensive historical records and relics have passed down from generation to generation. In particular, Cheomseongdae Observatory, built in 633 CE is one of the oldest observatories in the world.