17th C. Korean Map - "Paldo Jeondo" (八道全図)

Below is a Korean map of the Korean peninsula entitled "Paldo Jeondo" (八道全図), which is believed to have been made in the 1600s. The map is stored in Korea's Koryo University Museum.

On the map, Ulleungdo (鬱陵島) was drawn off the east coast of the Korean peninsula, and Usando (于山島) was drawn as a small island off the west coast of Ulleungdo, between the Ulleungdo and the peninsula. Off the southeast coast of Ulleungdo was written the following:

自此以東方日本
Japan is east of here.

The statement on the map agrees with a 1714 entry in the "Bo Gweol Jeong O" (補闕正吳), which was a supplement to the Records of King Sukjong (肅宗實錄). The record was as follows:

鬱陵之東 島嶼相望 接于倭境
Visible to the east of Ulleung is an island on the Japanese border.

In the report of his 1694 inspection of Ulleungdo (蔚陵島事蹟), Jang Han-sang wrote about climbing the central peak of Ulleungdo and seeing an island in the distance to the southeast that he judged to be less than one third the size of Ulleungdo. Later in the report, he summarized his observation by saying that he had looked toward "that country's (Japan's) territory" and saw no "imposing islands," which suggests that he did not consider the small, distant island he saw to the southeast to be "imposing." Here is what he wrote:

霽雨靄捲之日入山登中峯則南北兩峯岌崇相面此所謂三峯也西望大關嶺逶迤之狀東望海中有一島杳在辰方而其大未滿蔚島三分之一不過三百餘里

On a day the rain stopped and the fog lifted, we went into the mountains and climbed the central peak. Two tall peaks to the north and south were facing us. These were the so-called Sambong (三峯 - "Three Peaks"). The winding shape of the Dae Gwan Ryeong (大關嶺 - a mountain range on the east coast of the Korean peninsula) was visible to the west. Looking toward the east, there was one island far off to the southeast. The size was less than one-third that of Ulleungdo. It was only about 300 ri away.

(Later in the summary of the report)

登島山峰審望彼國之域則杳茫無眼杓之島其遠近未知幾許

If you climb the island's peak[s] and look closely at that country's (Japan's) territory, it is distant and hazy, and there are no imposing islands, so the distance (to mainland Japan) cannot be known.

The island referred to as being visible to the southeast of Ulleungdo was almost certainly Liancourt Rocks (Dokdo), which is ninety-two kilometers southeast of Ulleungdo. That means that Ulleungdo Inspector Jang Han-sang considered Liancourt Rocks to be part of Japanese territory.