Pyongyang, August 27 (KCNA) -- In Kaesong City of the Democratic People's Republic of Korea, there are the Phyochung Monuments and the Kaesong Chomsongdae Observatory, which were listed as the world's cultural heritages late in June this year. 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.