The Archaeological Institute of the Academy of Social Sciences, the Korean Agency for National Heritage Conservation under the Bureau for the Protection of Cultural Heritage at the Ministry of Culture, and the History Faculty of Songdo University of Education conducted a joint survey and excavation of the historical relics.

A mural tomb, identified as a royal-class mausoleum of the Koryo period, was found in the location about 1.2 km southwest from the seat of Haeson-ri.

The mausoleum is divided into four sections by three granite embankments tiered up on top of each other.

Located at the first section, which is at the highest point, are a piled-up tomb complete with stone parapet facilities and a pair of stone posts. The second and third sections, which are one tier lesser than the first, have a stone statue each and the fourth section has a place for memorial service.

The size of the tomb chamber, made with elaborately cut stones piled up together nicely, is 365cm in length from north to south and 300cm in width from east to west with a height of 235cm.

The eastern wall of the chamber has a hole, which can be seen in some married couple tombs, for the "soul" to move around, and its floor revealed pieces of the murals painted on the ceiling and walls of the tomb.

Discovered in the tomb are various relics such as parts of a jade book, carved with words praising the moral repute of the king and queen when giving them honorific titles, and gilded ironware.

The Archaeology Society of the DPRK identified the recently-unearthed tomb as a royal-class mausoleum made in the 14th century by studying its architectural style, size and relics. Over 250m away east from the tomb is the tomb of Princess An Phyong (unearthed in 1979), the wife of King Kyonghyo. And also recorded in various documents including the "Sinjungdonggukyojisungnam (Revised Handbook of Korean Geography)" are that the tomb of King Kyonghyo is about 3 miles west of the Kaesong area. With those facts in consideration, the society identified in agreement that the tomb can be seen as the mausoleum of the 25th king (1236-1308) of Koryo.

The discovery of the tomb of King Kyonghyo, the 25th king of Koryo, is conducive to enriching the treasury of national cultural heritage.