[1] A unique feature of it and the other extant tombs in the area are the wall paintings depicting blossoming lotuses, indicative of Buddhism practiced and perhaps prevalent in Korea around 277 BC to 668 AD.
[1][2] The sacred site was built when King Jangsu transferred his capital from the Hwando Mountain Fortress to Pyongyang in 427 AD.
Its history is traced to Goguryeo Kingdom which existed between 277 BC to 668 AD, initially in Huanren, Liaoning Province in China.
[1] Goguryeo had five ancient tribes each with its own ancestral tomb observing rites celebrated during the tenth month of every year by performing the tongmyong ("petition to the east") which is the worship of a heavenly deity named Susin.
Based on the discovery of the King's unicorn lair, archaeologists of the History Institute of the DPRK Academy of Social Sciences [ko] inferred that Pyongyang was the capital city of Ancient Korea and concurrently of the Goguryeo Kingdom.
[1] The legend behind the King's birth is told in the third-century Chinese historical text Weilüe, which is now mostly lost.
[9] According to Lankov, in the early 1970s, Kim Jong Il reportedly pointed to "a major shortcoming of North Korean archaeology: archaeologists had failed to locate the tomb of King Tongmyŏng".
[13][14] The alleged discovery of the burial place of the founding monarch of the Kingdom of Goguryeo was followed by an extensive "restoration" during the 1980s.
[12] The reconstruction process entailed the complete removal of all original buildings, structures, and monuments in order to create a new, white marble tomb.
The grounds include a large grassy area which was one of the venues for the 13th World Festival of Youth and Students.
The inscriptions found here proclaim that Changsu was the chief monk who conducted the rites at the tomb and also in the Buddhist monastery nearby.
It has three halls surrounding the walls of a pagoda which is similar to Japanese temples built in later years, suggesting that the Buddhism culture of Goguryeo has also permeated to Japan.
[3] The complex also houses the rebuilt Chongrŭngsa Buddhist temple, where funeral services were held for the deceased monarch.