Asia ’s earliest known observatory, Cheomseongdae Observatory was built in the 7 th century during the Silla dynasty, most likely as a way for geomancers to foretell fate.
Astronomers this day are uncertain as to how the tower was used but note that the tower is built with 365 stones, the number of days in a year; and that there are 12 rectangular basestones, the number of months in a year and the number of zodiac signs.