ancientart:

Cheomseongdae, meaning &ldquo;star-gazing tower&rdquo;, is an astronomical observatory in Gyeongju, South Korea. In 1962 Cheomseongdae was designated the country&rsquo;s 31st national treasure.
The sign near the structure reads:

Cheomseongdae was built during the reign of Silla Queen Seondeok (r. 632~647), and is the oldest astronomical observatory in East Asia.
The observatory is 5.17meters in diameter and 9.4meters in height. The bottle-shaped tower made of square granite stones stands on the square stone base. The length of the stone base is 5.35meters. Up to the 12th layer from the bottom, this hollow tower was filled with soil and pebbles. Between the 13th and 15th layer, there is a square opening through whi