The oldest surviving astronomical observatory in Asia, built during the Silla period in the 7th century. The cylindrical stone tower, 9.4 metres tall, is constructed from 362 blocks of granite arranged in 27 courses — the number representing the 362 days of the lunar year and the 27th king of Silla who commissioned it. The central window opening on the south side is aligned with the equinox sun.
Cheomseongdae sits in open parkland near the tomb complex, its elegant proportions making it one of the most photographed monuments in Korea despite (or because of) its apparent simplicity. Free to view from outside; no interior access. Best photographed at dawn or dusk.