Iriomote Island is the second-largest island in Okinawa Prefecture after Okinawa Island and the largest island in the Yaeyama Islands by area. Much of the island remains covered by dense subtropical jungle, creating a remarkably rich natural environment.
Mount Komidou, Mount Tedou, and Mount Goza are among the highest mountains in the Ryukyu Islands. Surrounded by mountains, rivers, mangrove forests, and tropical vegetation, Iriomote supports a unique ecosystem that includes the endangered Iriomote cat, a species found only on this island.
Because of its exceptional biodiversity and relatively untouched wilderness, Iriomote is often called the “Galápagos of the East.” In 2021, the island became part of the World Natural Heritage site covering the northern part of the Ryukyu Islands.
Iriomote is an ideal destination for travelers who want to experience Okinawa’s wilderness. Jungle trekking and kayaking tours take visitors deep into the island’s forests and waterways, offering opportunities to observe its distinctive plants and animals.
The island’s rivers are particularly important to the landscape. The Urauchi River and Nakama River flow through extensive mangrove forests, and guided canoe, kayak, and sightseeing boat tours provide an excellent way to explore these unique ecosystems.
The Urauchi River stretches for approximately 18.8 kilometers, making it the longest river in Okinawa Prefecture. The Nakama River is approximately 7.45 kilometers long. Both rivers are surrounded by extensive mangrove forests and provide some of the island’s most memorable nature experiences.
Visitors can travel by canoe or sightseeing boat through the calm waters while observing mangroves, tropical vegetation, and wildlife along the riverbanks.
At Hoshizuna-no-hama, or Star Sand Beach, visitors can search the sand for tiny grains shaped like stars. These distinctive grains are actually the calcareous remains of marine organisms and have become one of Iriomote’s most fascinating natural treasures.
The clear waters around the beach are also ideal for snorkeling and diving, allowing visitors to discover the colorful marine environment surrounding the island.
Approximately 90 percent of Iriomote Island is covered by natural subtropical forest, and around 80 percent of this forest is national forest. This extensive wilderness provides habitats for an extraordinary variety of plants and animals.
The island is home to the Iriomote cat and the crested serpent eagle, both specially protected species, as well as numerous other rare animals and plants.
Iriomote’s unique ecosystem supports numerous species designated as Special Natural Monuments or Natural Monuments of Japan. These include the Iriomote cat, Yonakuni pigeon, yellow-margined box turtle, and Kishinoue’s giant skink.
The island is also home to distinctive plants such as Iriomote Urokomizeni-goke and Iriomote Shamisenzuru. Their presence reflects the island’s long isolation and highly specialized natural environment.
Almost the entire island lies within the Iriomote-Ishigaki National Park. Particularly important areas, including the headwaters of the Urauchi and Nakama rivers and the region around Mount Takakomi and Mount Goza, are designated as Special Protection Zones covering approximately 4,624 hectares.
Iriomote is also home to a nationally designated wildlife protection area established to conserve rare species such as the Iriomote cat and Yonakuni pigeon. These protected areas play an essential role in preserving the island’s unique ecosystem.
Iriomote has a humid subtropical oceanic climate, remaining warm and humid throughout much of the year. Average monthly temperatures range from approximately 18.5°C in January upward, while annual precipitation reaches around 2,240 millimeters.
The combination of abundant rainfall, warm temperatures, and plentiful sunlight supports the island’s dense subtropical forests, rivers, mangroves, and diverse wildlife.
Historically, permanent settlement on Iriomote was difficult because malaria was widespread on the island. Nevertheless, settlements existed in places such as Komi and Sonai.
Coal mining was also carried out on the island in the early 20th century. However, the severe impact of malaria on workers eventually contributed to the suspension of mining operations.
During the final stages of World War II, residents of islands including Hateruma were forcibly evacuated to Iriomote. Many contracted malaria and died as a result.
This tragedy is remembered as wartime malaria. The history remains an important part of Iriomote’s past and is remembered by local communities today.
Iriomote’s extraordinary natural environment has made the island a popular destination for eco-tours. Local operators offer guided jungle treks, kayaking, canoeing, river cruises, snorkeling, and other activities that allow visitors to experience the island while learning about its ecosystems.
At the same time, the rapid growth of tourism has created environmental challenges. Waste disposal and sewage infrastructure have not always kept pace with increasing visitor numbers, making sustainable tourism and environmental conservation particularly important for the island’s future.
Iriomote has preserved distinctive local traditions alongside its remarkable natural environment. One of the most unusual is the Akamatā, Kuromatā, and Shiromatā festival held in the village of Komi.
During this sacred ceremony, figures representing deities descend from the mountains wearing vegetation over their bodies and masks in red, black, or white. The ritual is considered highly secretive, and photography, audio recording, and sketching are prohibited.
Iriomote also has a distinctive food culture based on ingredients from the island and surrounding waters. Local specialties include Ryukyu wild boar, sawagani crab, and island octopus.
Because many of these ingredients are rarely distributed outside the island, trying them locally can be a particularly memorable part of an Iriomote journey.
Iriomote has several elementary and junior high schools, but there is no high school on the island. Students generally leave Iriomote to attend high school elsewhere after completing junior high school.
This reflects the distinctive lifestyle of an island community where daily life remains closely connected to the surrounding natural environment and the wider Yaeyama Islands.
Iriomote Island offers a rare opportunity to experience one of Japan’s most extensive areas of subtropical wilderness. From dense jungle and ancient mangrove forests to clear tropical waters and secluded waterfalls, the island is filled with landscapes that feel far removed from urban Japan.
Whether paddling through a mangrove river, trekking through the jungle, searching for star-shaped sand, snorkeling in clear coastal waters, or learning about the island’s rare wildlife, visitors can experience nature in an unusually direct and immersive way.
As part of the World Natural Heritage area of the northern Ryukyu Islands, Iriomote is not simply a sightseeing destination but a precious natural environment that requires careful protection. Respecting local communities, wildlife, and conservation rules is an important part of enjoying this extraordinary island.
Fly to Ishigaki Island from various places,
From Ishigaki Island to Iriomote Island, take a boat.
It takes about 45 minutes from Ishigaki Port Terminal to Uehara Port.
From Ishigaki Port Terminal to Ohara Port: about 35 minutes