Cheomseongdae Observatory

Cheomseongdae is a bottle-shaped tower of cut granite about nine metres high, raised in the reign of Queen Seondeok in the middle of the seventh century, and it has stood on the same ground ever since - never dismantled, never rebuilt, which is what makes it remarkable rather than its size. The numbers in it are read as deliberate: roughly 362 blocks for the days of a lunar year, twelve courses below the window and twelve above for the months, twenty-seven courses for Seondeok as the twenty-seventh ruler. A square window halfway up faces south. Whether it worked as an observatory in a practical sense, or as a ritual and calendrical monument, or both, is still argued by specialists - the interior is filled with rubble to the window and there is no record of how it was used. It sits alone in an open field which the city plants with flowers, and it is lit at night.

What to look for

• The granite tower - nine metres, unrebuilt since the 600s.
• The counted courses - the blocks read as a calendar.
• The south window - the square opening halfway up.
• The open field - flowers in season, the tower lit at night.

When to go

April to June and September to November; the flower field peaks in autumn. Night, when it is lit, is the local favourite. Fifteen minutes covers it.

What to expect

You cannot go inside or approach past the barrier - it is viewed from the surrounding field. There is very little on site to explain it. It is one object, and quick.

Nearby

Daereungwon, Gyeongju's old town and Wolji pond are all within walking distance.

Key facts