terravelJapan · Asia
Tsushima Island
What is Tsushima Island, and where is it?
Tsushima is an archipelago in Japan's Nagasaki Prefecture, located in the straits between Kyushu and the Korean Peninsula, approximately 50 km from Busan. Once a single landmass, it was deliberately divided by two canals—in 1671 and 1900—into three distinct parts: North Tsushima, South Tsushima, and a connecting strip, plus over 100 smaller islands.
Position Between Two Nations
Tsushima sits in the Korea Strait and Tsushima Strait, roughly equidistant between Kyushu and the Korean Peninsula. The archipelago measures about 70 by 15 kilometers and covers 696 square kilometers. On clear days, the hills and mountains of Korea are visible from the island's higher elevations. The nearest Japanese port, Iki Island, lies 50 kilometers away. Tsushima and Iki are jointly protected as the Iki–Tsushima Quasi-National Park, a nature preserve designated to prevent further development. Administratively, Tsushima belongs to Nagasaki Prefecture, though it functions as a single entity despite the artificial waterways that separate it into distinct islands.
The Korea Strait splits at the archipelago into two channels: the wider Tsushima Strait runs closer to Japan's mainland, while the narrower Korea Strait runs toward the peninsula. This geographic position made Tsushima a threshold between two civilizations for centuries. The archipelago comprises over 100 smaller islets in addition to the main islands. The total population as of 2022 was approximately 28,000, with a demographic trend showing decline—the population decreased 9.4 percent between 2015 and 2020.
Canals That Reshaped the Landscape
Two deliberate canals transformed Tsushima's physical form. The Ōfunakoshi-Seto canal, cut in 1671, first divided the island into two parts. The Manzeki-Seto canal, driven through in 1900, created a third section. Both canals were carved through isthmuses in the island's center and connect the deep indentation of Asō Bay on the island's east side. These waterways created North Tsushima (Kamino-shima) and South Tsushima (Shimono-shima), now joined by a combination bridge and causeway. The canals remain visible evidence of human intervention in the landscape, yet the island retains profound natural character.
North Tsushima contains Mi-take mountain at 487 meters. South Tsushima holds Mount Yatate at 649 meters and Ariake-yama at 558 meters. The island group also includes mountains such as Mt. Ohira, Mt. Hokogatake, Mt. Koyasan, Mt. Ontake, and Mt. Gogen. Approximately 89 percent of Tsushima is covered by natural vegetation and mountains, with forests covering roughly 90 percent of the total area. Broad-leafed evergreens, conifers, and deciduous trees including cypress dominate the forest composition. The steep slopes and small, isolated geography expose the island to moist marine air on all sides, resulting in higher rainfall than Japan's main islands.
Strategic Intermediary in East Asian Trade
Tsushima's significance stems from its role as a controlled gateway between Japan and Korea. From the early sixth century, it functioned as an official Japanese province. During the feudal period, the Sō clan governed the island and monopolized trade with Korea under agreements like the 1443 Treaty of Gyehae. After the Imjin War (1592–1598), the Kiyu Agreement of 1609 formalized trade and diplomatic exchanges, with Tsushima serving as the exclusive intermediary for Japan's contact with the Joseon court. The island became economically dependent on Korean grain imports, with reports suggesting over half of Tsushima's rice consumption came from Korea. The Waegwan (Japan House) in Pusan institutionalized these interactions as a hub for controlled trade and diplomacy.
The island's institutions reflected its liminal position. Tsushima used a unique land taxation system (Kendaka) derived from Chinese and Korean methods rather than Japan's standard kokus-based system, reflecting its economic ties to Korea. Unfree labor existed as an established institution on Tsushima, as it did in Korea, though it was rare elsewhere in Japan. The Tsushima dialect incorporated Korean loanwords, and daily customs, social structure, and economic interactions blended Japanese and Korean elements. This arrangement persisted throughout the Tokugawa period until the Meiji Restoration, when Tsushima was transferred to Nagasaki Prefecture in 1872.
Tsushima Reef and Endemic Wildlife
Tsushima Reef, located in the bay between Tsushima and Iki Island, is the northernmost coral reef in the world. It is dominated by cool-tolerant stony or Scleractinian Favia corals. Tropical Acropora coral has been observed settling on the reef, providing an ongoing indicator for global warming trends. The reef's existence at this latitude reflects the island's position in a transitional marine environment influenced by monsoon winds and ocean currents.
Land animals recorded on Tsushima include the leopard cat, Japanese marten, Siberian weasel, and several rodents. Otters were discovered living there in February 2017. Migrating birds that stop over include hawks, harriers, eagles, and black-throated loons. The Tsushima pitviper is a venomous snake endemic to the archipelago. Tsushima has been recognized as an Important Bird Area by BirdLife International because it supports populations of Japanese wood pigeons and Pleske's grasshopper warblers. Honey bees are common on the island, with many used to produce commercial honey. Flora includes Yoshino cherry and Chionanthus retusus.
Modern Economy and Tourism Shifts
Fishing dominates Tsushima's primary industries, accounting for 82.6 percent of primary sector employment. Squid fishing on the eastern coast is particularly significant. According to a 2000 census, 23.9 percent of the population worked in primary industries, 19.7 percent in secondary industries, and 56.4 percent in tertiary industries. Employment in primary industries has declined while secondary and tertiary sector jobs have grown. Tourism, particularly from South Korea, has recently contributed substantially to the local economy. A high-speed ferry service from Busan launched in 1999, dramatically increasing Korean visitor numbers. In 2008, 72,349 Koreans visited; Korean tourists generated an estimated ¥2.1 billion in annual revenue and approximately 260 jobs.
Tourism patterns shifted significantly after 2019. In 2018, 90 percent of visitors were from South Korea, but an 88 percent decrease in Korean visitors occurred in 2019 following a trade war between Korea and Japan over chemical exports and historical reparations disputes. The COVID-19 pandemic further reduced tourism. Since 2020, the island has gained popularity as a tourist destination due to the video game Ghost of Tsushima, with visitors seeking locations featured in the game and local culinary specialties including rokube noodles, ishiyaki, tonchan, and anago conger eel.
Tsushima Island at a glance
Questions about Tsushima Island
Why were canals cut through Tsushima Island?
The Ōfunakoshi-Seto canal was cut in 1671 and the Manzeki-Seto canal in 1900, both driven through isthmuses to connect Asō Bay on the island's east side. The source does not specify the original reasons for these engineering projects, only that they deliberately divided the once-single landmass into three distinct parts.
What is the climate like on Tsushima?
Tsushima has a marine humid subtropical climate influenced by monsoon winds. Average temperature is 15.8°C (60.4°F), with average yearly precipitation of 2,132.6 mm. The highest recorded temperature is 36.6°C (97.9°F) in August 2013; the lowest is −6.8°C (19.8°F) in 1895. The island is typically 1–2°C cooler than Nagasaki city.
How did Tsushima's institutions differ from the rest of Japan?
Tsushima used a unique land taxation system (Kendaka) based on Chinese and Korean methods rather than Japan's standard kokus system. Unfree labor existed as an established institution, rare elsewhere in Japan. The Tsushima dialect contained Korean loanwords, and daily customs, social structure, and economic interactions reflected Korean influences due to centuries of trade dependency and cultural exchange.
What happened to Korean tourism to Tsushima after 2019?
Korean visitor numbers dropped 88 percent in 2019 following a trade war between Korea and Japan over chemical exports and historical reparations disputes. The COVID-19 pandemic further reduced tourism. In 2018, 90 percent of visitors were from South Korea, but this proportion changed dramatically after these events.
What makes Tsushima Reef geographically significant?
Tsushima Reef, located in the bay between Tsushima and Iki Island, is the northernmost coral reef in the world. It is dominated by cool-tolerant stony corals, with tropical Acropora coral settling observed, providing an indicator for global warming trends in marine ecosystems.
Sources and further reading
This article was written from the reference material below, retrieved and reviewed for source alignment on September 13, 2026. Use official local sources for changing access or travel information.
About this page. Terravel combines its curated place catalog with credited photography and geographic reference data. Practical travel details can change; use the linked destination guide and official local sources when planning a trip. Send a correction.
Test yourself
Which Asian island was deliberately split into three separate parts by canals carved through isthmuses in 1671 and 1900?
Tsushima Island, Japan, was physically divided by human-engineered canals that cut through isthmuses, creating North Tsushima, South Tsushima, and a third section—a rare example of landscape transformation through deliberate waterway construction.
Can you place today's?
Tsushima Island is one of 266 places in Terravel. A new one every morning.
