This astronomical observatory, now designated as the Treasure No. 851, was built in 1688 to observe the movement of heavenly bodies via using an armillary sphere. The observatory was managed by the Meteorological Office (Gwansanggam), a government agency responsible for the observation of the movement of the sun, moon, and stars, change of time according the change of seasons, and the twenty-four solar terms. The information gathered by the agency was productively exploited by the farmers of Joseon.