There is a large cave to the east of Gimnyeong Village. It is said that an enormous serpent used to live inside there, so it came to be called Snake Cave. The snake was as thick as an earthenware jar that holds five large bags of rice.
Each year the people of Gimnyeong performed a special ritual in which they sacrificed a virgin girl to the snake. If for some reason they failed to perform the ritual, the creature would come out of the cave and trample over the surrounding fields of grain, leading to a year of famine. So the people of the village had no choice but to be sure to sacrifice one of their young women each year. The upper class was reluctant to give up their daughters in this way, so the young woman was usually chosen from the families of shamans and other lower class citizens. As a result, their daughters had trouble finding husbands.
During the reign of King Jung-Jong, a man named Seo Yeon was sent to the island to begin work as a judge. He was nineteen years old at the time. Judge Seo became infuriated upon hearing the strange rumors about the yearly sacrifice at Snake Cave in Gimnyeong. When the time came, he prepared the alcohol and rice cakes necessary for the sacrifice, and ordered a virgin girl to be brought forth.
Judge Seo went in person to Snake Cave, bringing some soldiers with him. They started the sacrificial ceremony, and after a while the enormous snake, of course, came out and began eating the rice cakes and drinking the alcohol. Just as the beast turned to snatch and devour the young woman, Judge Seo and his soldiers leaped at the creature and killed it with their swords and spears.
There are two versions of what happened next.
One story tells us that a shaman who witnessed the events told the judge “Mount your horse and ride straight back to the city. No matter what happens, you must not look back.” Judge Seo got his whip and rode his horse in the direction of Jeju City. He arrived at the eastern gate without incident, but as he was about to enter, one of the soldiers shouted “There’s a rain of blood falling behind us!” “What rain? What do you mean by a ‘rain of blood’? I’ve never heard of such a thing!” Without thinking, Judge Seo carelessly looked backwards, and at that very instant he fell off his horse and died on the spot. When the snake died, its blood had risen up into the sky, mixed with the rain and gone chasing after its executioner.
Another version of the story says that after killing the snake and ridding Jeju of the evil practice of the yearly sacrifice, Judge Seo left the island, setting off for the mainland by boat. He got as far as the uninhabited island of Saseokoji between Jeju and Chuja Island, where he died in a shipwreck. The ghost of the snake had taken its revenge. It was after that incident that Jeju fishermen began performing the ritual of offering up a pig’s head to the snake spirit when they reach Saseokoji. To this day, people still perform that ritual.
As recounted on February 25, 1975, by Mr. An Yong-In (안용인, 65) of West Gimhak-ri, Gujwa-myeon, and on August 28, 1972, by the Jo (조) family of East Gimhak-ri, Gujwa-myeon.
From 99 Legends of Jeju Island, a compilation based on accounts compiled by Hyun Yong-Joon.
Chuja Island : Chuja-do : 추자도 : 楸子島
Seo Yeon (서연 : 徐憐, also pronounced Seo Rin: 서린) was a pangwan (판관: 判官), which was a government position in the Goryeo (918-1392) and Joseon (1392-1897) dynasties encharged with providing counsel and assistance to the lead administrator of a district in matters related to civil affairs. The same term is used today for the modern position of judge. There is a monument commemorating Judge Seo that stands in front of Snake Cave.
King Jung-Jong (중종: 中宗) reigned from 1506 to 1544.
The ritual is called a gut (굿). They are performed by shamans for various reasons, such as praying for a good catch at sea and a bountiful harvest on land, asking the gods and spirits to assist in the alleviation of illness, and praying for the success of a new business. Gut are still practiced in Korea today.
Saseokoji : 사서코지
Snake Cave : Sagul : 사굴 : 蛇窟
This cave is also called Baemgul (뱀굴), but is most commonly known today as Gimnyeong Sagul. It is closed to the public, but you can see the entrance on the east side of the road heading north from Manjang Cave (Manjang-gul: 만장굴: 萬丈窟).