The Phyochung Monuments were built on the instructions of kings of the Feudal Joson Dynasty (1392-1910), in memory of Jong Mong Ju who was assassinated on Sonjuk Bridge for his refusal to betray the government of Koryo Kingdom (918-1392). One of them in a pavilion was erected on King Yongjo's order and the other on King Kojong's order.

Both of the monuments are put on stone-made turtle sculptures weighing over 10 tonnes each. What catches the eyes are backs of the turtles carved with patterns of lotus flowers, which represent the high-level sculpture skills.

The Kaesong Chomsongdae Observatory was built with well-trimmed pieces of stones in 919, as the central astronomical observatory of Koryo Kingdom.

There remains now only a granite-built embankment, 2.8 meters high and 2.6 meters long.