Rukhwasokpho was the high-angle cannon used in the closing years of Koryo dynasty, which fired round stone balls.

   Its name derived from the fact that it emitted six colours of flames (red, yellow, green, blue, dark blue and purple or yellowish brown when firing.

   It was mass-produced in 1032 and between 1122 and 1127 and deployed in the fortresses across the country. It was also called Roedungsokpho, which means that it sounded like lightning and thunder when firing.

   It was designed to be set according to the required angle of fire and azimuth and do high-angle fires.

   It was a built-up cannon to be easily moved and handled in the physiographical conditions of Korea. Made of bronze until the period of Koryo dynasty and iron later, it was used in the fight against foreign invaders.

   It is one of the inventions showcasing the resourcefulness and talents of the Korean ancestors.