Days of downpour have flooded dozens of cultural properties across the country, breaking an ancient stone stele and damaging royal tombs.

At Gongju, the ancient capital of Baekje between AD 475 and 538, excavation sites at Seokjang-ri, where Paleolithic relics were found for the first time in Korea, and parts of a mountain castle were inundated and damaged.

At the fortress Gongsanseong built some 1,500 years ago in Gongju, South Chungcheong Province, only the roof of the Manharu pavilion at the lower part of the UNESCO World Heritage site could be seen above water on Saturday.

Torrential rain washed down soil and rubble at the Geumseoru gate on the western side of the fortress, breaking one of the many stone steles nearby.

The Geum River which runs next to the fortress often overflows into the heritage site at times of heavy rainfall or typhoons, according to an official at the Cultural Heritage Administration.

“Due to the frequent overflowing, the grounds at Gongsanseong are not very firm to begin with. Loss of soil has often taken place,” Seo Min-seok, a CHA official handling risk management, told The Korea Herald.

“But this is the first time water levels went up so high.”

Parts of ancient burial mounds were washed down in Suchon-ri, Gongju, and at the Buyeo Royal Tombs in nearby Buyeo, which served as Baekje’s last capital from AD 538 to 660.

When an ancient tomb of great historical and academic value in Gyeongju, North Gyeongsang Province, lost some of its soil due to Typhoon Hinnamnor last year, it cost over 100 million won ($78,800) to restore it, according to Seo.

In Seoul, a wall made of stone bricks on a hill slope behind Injeongjeon, the main hall of Changdeokgung, crumbled down on Friday.

As of Sunday morning, a total of 31 cases of damages were reported at cultural heritage sites due to torrential rain since June 23, the CHA said.

They include national treasures such as the three-story stone pagoda in Sincheon-ri, Yeonggwang, South Jeolla Province; Mungyeong Saejae, a historical mountain pass in North Gyeongsang Province; and Andong Hahoe Folk Village in North Gyeongsang Province.