The Koksan is a self-propelled howitzer of North Korean origin. It was designed for very long range shelling and for several decades was the longest range conventional artillery piece in use. The name Koksan is derived from the city it was first spotted. The original designation is not known.

The Koksan is based on the Type 59 tank chassis and mount a very large 170mm gun which is believed to be an ex-Russian naval or coastal artillery gun. The gun is mounted in an open superstructure and is stabilized by two large spades at the rear. An improved model is based on a chassis similar to the Soviet 2S7 Pion and carries more ammunition.

The massive 170mm gun fires very powerful shells. The range of standard shells is believed to be about 40 km and rocket assisted shells can be fired out to 60 km. The range and firepower is offset by a very low rate of fire of up to 2 rounds per 5 minutes.

The Type 59 chassis is armored but only provides protection for the driver. The gun crew is not carried on the Koksan and in the firing position the crew is fully exposed. The only protection that is provided is the ability to use the weapon well behind the front line due to its long range.

The Type 59 chassis provides a reasonable mobility on roads and in the field. The maximum road speed is estimated a 40 km/h. The high center of gravity and large gun make it difficult to travel in the field.

North Korea has up to 500 large caliber guns. The Koksan makes up an unknown portion of these guns. A number of M1978 was exported to Iran and was extensively used in the Iran-Iraq war.