Why Hashima Island Was Abandoned: Coal, Decline, and UNESCO Heritage

Hashima Island: From Bare Rock to Self-Contained City

Hashima Island (端島, Hashima) — more commonly known as Gunkanjima (軍艦島, Battleship Island) for the warship-like silhouette of its concrete skyline — is a small islet 4.5 kilometres off the coast of Nagasaki. It began its modern history as an uninhabited rock. It ended it as one of the most densely populated places on earth, then became a ghost island overnight. Understanding why it was abandoned requires understanding what it was built for and why that purpose became economically impossible.

Hashima's history as part of Nagasaki's broader industrial story is one of Japan's most compressed narratives of industrialisation and decline. For the wider context of Nagasaki's history — from its Dutch trading post to its atomic bomb legacy — see our guide to Nagasaki history and memorial sites. Hashima's industrial coal history is distinct from Nagasaki's wartime atomic bomb history, which is covered separately by the Nagasaki Atomic Bomb Museum.

The Coal Discovery and Mitsubishi's Takeover in 1890

Coal was discovered beneath the seabed around Hashima Island in the mid-19th century. The Fukahori family began shallow excavation in the 1870s, but the scale of the operation changed entirely when Mitsubishi purchased the island in 1890 and began developing it as an industrial coal mining operation. Mitsubishi (三菱炭鉱, Mitsubishi Tankō) would operate Hashima continuously for 84 years, transforming it from bare rock to a fully self-contained industrial community.

During Nagasaki's Meiji-era modernisation — the same period when Western-style merchants were building the mansions now preserved at Glover Garden — Hashima was becoming an undersea coal mine unlike anything previously built in Japan. The coal seams ran beneath the ocean floor, requiring deep shafts and sophisticated drainage systems to extract. It was technically demanding work that shaped every aspect of life on the island.

How Mitsubishi Transformed Hashima: Coal, Concrete, and Community

Japan's First Concrete Apartment Buildings

As Hashima's coal production grew, so did its workforce — and a workforce on an island 4.5km offshore cannot commute. Mitsubishi built permanent housing on the island, and the scale of construction required increasingly efficient solutions for limited land. In 1916, Mitsubishi completed what is widely cited as Japan's first reinforced concrete apartment building on Hashima, a seven-storey structure that solved the problem of housing a growing industrial workforce on a minimal footprint.

The 1916 building was the start of a decades-long construction programme that eventually covered virtually every square metre of the island in concrete structures: apartment blocks stacked against each other, connected by elevated walkways, built to withstand the typhoons that regularly hit the exposed offshore rock. By the time construction was complete, Hashima looked from a distance like a grey concrete vessel — which is where the Gunkanjima nickname originated, a reference to the battleship Nagato.

A Self-Sufficient Island: Schools, Hospital, and Shops

A mining workforce living on an offshore island requires everything that a mainland city provides. By its peak period, Hashima had its own elementary and middle schools, a hospital, a cinema, a pachinko parlour, shops, and a rooftop garden where residents could grow vegetables. The island had its own electricity generation and water desalination — connections to the mainland were for coal export and worker transport, not for basic utilities.

This self-sufficiency was not a luxury but a practical necessity. Workers and their families could not leave the island for daily needs. The infrastructure built to support the coal operation was comprehensive enough that Hashima functioned as an independent urban settlement for the better part of a century.

Life at Peak Population: What It Was Like to Live on Gunkanjima

Hashima's population peaked in 1959, when according to Nagasaki City official records, the island housed more than 5,300 people. At that density — approximately 835 people per hectare on the inhabited portion of the island — Hashima was one of the most densely populated places on earth. For context, the most crowded urban districts in Tokyo today have densities several times lower.

Life in that density had its own character. Apartments were small; the shared infrastructure — schools, hospital, shopping street — was proportionally more important than in a mainland city. Residents recall strong community bonds formed by physical proximity and economic dependence on the same employer. Children played on the rooftops and elevated walkways. Social life centred on the island's communal facilities. For the miners themselves, work meant descending into shafts below the ocean floor — an experience unlike any surface mine.

By the early 1960s, however, the conditions that had made Hashima viable were beginning to change.

Why Hashima Was Abandoned: The Coal-to-Oil Energy Shift

Japan's Post-War Energy Policy and the Decline of Coal

Hashima Island was abandoned in 1974 not because it ran out of coal — it didn't — but because the coal it contained was no longer economical to extract. The reason was Japan's post-war energy transition from domestic coal to imported petroleum.

Japan's coal industry had been strategically central to the country's post-war reconstruction. Domestic coal powered the factories and infrastructure rebuilding that drove Japan's economic recovery in the late 1940s and 1950s. Hashima's annual production — approximately 300,000 tonnes at peak, according to Mitsubishi's own records — was part of a nationwide industry that was nationally prioritised.

Coal Production Could Not Compete with Cheap Oil

The problem was that from the late 1950s onward, the global price of oil fell sharply, and Japan's industrial economy shifted its energy source accordingly. Imported oil was cheaper, cleaner to handle, and more energy-dense than coal. Japanese industry retooled for oil-powered production, and government energy policy followed. The domestic coal industry lost its strategic protection.

For an undersea mining operation like Hashima — which required expensive infrastructure, deep shaft maintenance, and a permanent residential workforce — the economics were particularly severe. Surface coal mines could cut costs more easily; an offshore undersea operation with a population of several thousand people to house and support had fixed costs that made it structurally uncompetitive once oil became the preferred fuel. The mine closure (閉山, heisan) was not about depletion. It was about a global energy shift making the operation economically impossible to continue.

The 1974 Closure: What Happened When Mitsubishi Shut Down

January 15, 1974: The Announcement

On January 15, 1974, Mitsubishi formally announced the closure of the Hashima coal mine. The decision had been anticipated — coal industry contractions had been visible for over a decade, and many of Hashima's miners had already transferred to other Mitsubishi facilities or left the island in the years preceding the announcement. By 1974, the island's population had already declined significantly from its 1959 peak of 5,300, as the workforce shrank with production.

The announcement confirmed what residents had feared. The mine was finished. The island that had sustained itself as an economic unit for 84 years would close.

April 20, 1974: The Last Residents Leave

The departure was rapid. According to Japanese records, the last permanent residents of Hashima Island departed by boat to Nagasaki on April 20, 1974 — roughly three months after the mine closure announcement. The island went from inhabited to empty within a season.

Residents took their personal possessions but left behind everything that had made Hashima a functioning city: the school desks, the hospital equipment, the cinema seats. The infrastructure that could not be carried was simply left. There was no extended decommissioning process, no gradual wind-down — the population departed, and the buildings began their long deterioration in the salt air of the East China Sea.

Hashima has been uninhabited since April 20, 1974.

From Ruins to UNESCO: Hashima Island's World Heritage Designation

The 2015 UNESCO Inscription

Hashima remained a closed, off-limits island for decades after its abandonment. Portions of the site began opening to boat-based tourism in the 2000s, and international attention — partly driven by the 2012 James Bond film Skyfall, which used Gunkanjima as a visual reference for its villain's island hideout — raised global awareness of its existence.

In 2015, Hashima Island was inscribed as part of the Sites of Japan's Meiji Industrial Revolution: Iron and Steel, Shipbuilding and Coal Mining UNESCO World Heritage group (明治日本の産業革命遺産). The inscription recognised Hashima for its role in Japan's rapid industrial modernisation, specifically for its pioneering undersea coal mining techniques and as evidence of the speed with which Japan transformed its industrial capacity in the late 19th and early 20th centuries. The Glover Garden heritage site is part of the same Meiji Industrial Revolution inscription, connecting Hashima to Nagasaki's broader Meiji-era industrial history.

The Wartime Forced Labor Controversy

The 2015 UNESCO inscription was not without controversy. South Korea objected to the nomination on the grounds that the inscription recognised sites — including Hashima — where Korean workers had been brought under compulsion to work in the mines during World War II. The dispute was significant enough to delay the inscription process and required diplomatic negotiation between Japan and South Korea.

As part of the 2015 inscription process, Japan committed to acknowledging the wartime forced labor history (強制連行, kyōsei renkō) at the inscribed sites and to establishing an information centre addressing it. The inscription thus simultaneously recognised Hashima's industrial heritage significance and created a formal record of its most contested historical chapter.

The coexistence of industrial heritage recognition and wartime labor history at Hashima is part of what makes it a more complicated site than its pop culture image — as a picturesque ruin or a cinematic location — suggests.

Frequently Asked Questions

Why was Hashima Island abandoned?

Hashima Island was abandoned in 1974 because Japan's post-war energy policy shifted away from domestic coal toward cheaper imported oil. The island's undersea coal mining operation, despite still containing coal reserves, could no longer compete economically. Mitsubishi — which had operated the mine since 1890 — announced the closure on January 15, 1974, and the island's remaining population departed by April of that year.

When was Hashima Island abandoned?

Mitsubishi officially announced the mine closure (閉山) on January 15, 1974. The island was formally evacuated when the last residents departed by boat to Nagasaki on April 20, 1974. Hashima has been uninhabited since that date, though portions of the island are now accessible to boat-tour visitors.

What happened to the people who lived on Hashima Island?

The residents still living on Hashima at the time of the 1974 closure — a number that had already declined significantly from the 5,300+ peak of 1959 — relocated to Nagasaki and elsewhere on the Japanese mainland. The departure was rapid: within roughly three months of the mine closure announcement, the entire remaining population had left. Residents took personal belongings but left behind the island's full infrastructure — schools, hospital, apartments, and shops.

Why did Hashima Island become a UNESCO World Heritage Site if it was abandoned?

Hashima Island was inscribed as part of the 'Sites of Japan's Meiji Industrial Revolution' UNESCO World Heritage group in 2015. The inscription recognises the island for its role in Japan's rapid industrial modernisation — specifically its pioneering undersea coal mining and Japan's first reinforced concrete apartment buildings, both of which represent significant industrial heritage. The state of abandonment preserves rather than diminishes the historical record.

Is Hashima Island's UNESCO status controversial?

Yes. The 2015 UNESCO inscription was disputed because of Hashima's wartime history of forced labor, when Korean and Chinese workers were brought to the island under compulsion to work in the mines during World War II. South Korea objected to the nomination, and Japan agreed as part of the inscription process to acknowledge this history formally and establish an information centre addressing it. The site's significance and its contested wartime history coexist within the same UNESCO designation.