Cheomseongdae Observatory

Cheomseongdae Observatory is a cylindrical stone tower rising about nine meters above the ground, characterized by its distinctive bottle shape that tapers toward the top. Built during the seventh century in the reign of Queen Seondeok, it is recognized as the oldest surviving astronomical observatory in East Asia. The structure is composed of precisely stacked granite blocks, with a square window positioned mid-height that served as an entrance for early observers who likely used a ladder to reach the upper platform.