Wikipedia
Honcheonsigye
The Honcheonsigye is an astronomical clock created by Song I-yeong in 1669. It is designated as South Korean national treasure number 230.
The clock has an armillary sphere with a diameter of 40 cm. The sphere is activated by a working clock mechanism, showing the position of the universe at any given time.
The clock is owned by Korea University. It is the only remaining astronomical clock from the Joseon Dynasty.
An image of the clock's sphere is shown on the reverse of the 2007 issued 10,000 won banknotes: