Literally meaning "Star Gazing Tower," this stone's astronomical observatory is commonly accepted as the most important structural remains in Korea. It dates back to the three kingdom period prior to the unification. This observatory is considered the oldest existing observatory in the Far East. Having become symbolic of Korea itself, Cheomsongdae (Near the Stars Place) is frequently pictured on travel posters and in tourist guide books.

Designated by the Korean government as National Treasure No.31, this 29 foot stone observatory is mounted on a 17 foot square foundation. It is believed that a ladder was used to reach this entrance as worn marks on the stone can be observed.

From this window level another ladder or staircase was very likely placed inside the observatory so that the top of this structure could be reached.

Within the structure of the upper half of the observatory are two sets of stone bars arranged parallel to each other. One set is positioned directly above the window opening and the other near the top. The ends of these parallel supporting stones can be seen jutting out several inches from the circular surface of the observatory. These stone bars might have served as a type of support for a staircase to reach the top.

Cheomsongdae was constructed during the reign of Queen Seonduk, 27th ruler of Silla. It is certainly appropriate that this stone observatory has become a national symbol of Korea for it is known that from Korea's early history there has always been a preoccupation with the stars. Early views of the universe and life itself has been largely dictated by the stars and their movements.

Often what was believed to be astrology regarding the heavens turned out to be scientific discovery. This continuing desire to observe the stars and their relationship with each other often resulted in certain predictable events.

For well over two thousand years the movements of the stars and known planets were carefully studied and charted. Solar and lunar eclipses were predicted as well as the course of comets which came within view of the Silla astronomers. When the court astrologists reported and interpreted their findings, the king would then proceed to act according to their predictions. The waging of wars, restrictions, agricultural developments, celebrations and just about every known aspect of royal policy making was governed according to the study and interpretation of the stars.

In general, most Koreans believe that the exact time of birth for each person is closely governed by the heavens. A particular year, month, day, hour and even minute is strongly believed to link the new baby to certain unchangeable influences and patterns of living which are historically developed astronomic combinations. In other words, a small child's destiny is already set. These astrological calculations have been recorded in Korean astrology manuals which today are extensively used by the fortunetellers in what is a lucrative business in modern Korea.

The total number of stones used has been known as 365, the number of days in a calendar year.

These 12 rectangular base stone positioned in a square, three to each side are representing the twelve months of the year and the four seasons. There are twelve tiers of stones to the sill stones of the window entrance and twelve tiers above the window opening. The window space is within the three stone tiers which makes a total height of the observatory 27 tiers. Queen Seonduk was the 27th ruler of Silla and this observatory was built during her third year of reign in 634. The use of the twelve tiers above and below the window opening might symbolize the zodiac or possibly the months of the year. But exactly how it was used is still a mystery.