---
node: spot_gyeongju_cheomseongdae
type: spot
slug: cheomseongdae
destination: dest_gyeongju
title: "Cheomseongdae"
lead: "Cheomseongdae is a stone tower of 634 AD, generally held to be the oldest surviving astronomical observatory in East Asia. It is built of 362 cut stones, about the number of days in a lunar year."
published: 2026-08-12
updated: 2026-08-12
image_file: spot_gyeongju_cheomseongdae.jpg
image_source: "https://commons.wikimedia.org/wiki/File:CheomseongdaeModel2.jpg"
image_author: "Straitgate (talk) (Uploads)"
image_license: "CC BY-SA 3.0"
---

## Overview

The bottle-shaped tower is nine metres high, with a window facing south at the middle level and a square frame on top that may have held instruments. Its numbers are widely read as calendrical — twelve courses below the window and twelve above for the months, twenty-seven courses for the twenty-seventh ruler of Silla, Queen Seondeok, who had it built. How exactly it was used is not known, and honest accounts say so.

## Highlights

It stands alone in a field and takes ten minutes; the point is to walk around it and see how the curve is made of straight courses. It is lit after dark and photographs better then. Cheomseongdae, Wolji and Daereungwon are within a fifteen-minute walk of each other and make one evening.