In 1974, with the coal reserves nearing depletion, the mine was closed and all of the residents departed soon after, leaving the island effectively abandoned for the following three decades.

In 1916, the company built Japan's first large reinforced concrete building (a 7-floor miner's apartment block),[8] to accommodate their burgeoning ranks of workers.

Over the next 55 years, more buildings were constructed, including apartment blocks, a school, kindergarten, hospital, town hall, and a community centre.

For entertainment, a clubhouse, cinema, communal bath, swimming pool, rooftop gardens, shops, and a pachinko parlour were built for the miners and their families.

[15] Today, its most notable features are the abandoned and still mostly-intact concrete apartment buildings, the surrounding seawall, and its distinctive profile shape.

In addition a visitor walkway 220 meters (722 feet) in length was planned, and entry to unsafe building areas was to be prohibited.

Additionally the city encountered safety concerns, arising from the risk of collapse of the buildings on the island due to significant ageing.

[17] A full reopening of the island would require substantial investment in safety, and detract from the historical state of the aged buildings on the property.

[24][25] On 5 July 2015,[4] at the 39th UNESCO World Heritage Committee (WHC) meeting, South Korea formally withdrew its opposition to Hashima Island being on the list.

[25][4][26][27][28] Japan also claimed to be "prepared to incorporate appropriate measures into the interpretive strategy to remember the victims such as the establishment of information centre".

[30] Immediately after the UNESCO WHC meeting, Japanese Foreign Minister Fumio Kishida rejected the idea that Koreans were "forced laborers", and claimed that they were instead "requisitioned against their will" to work.

[33] The Japanese politician Kōko Katō [ja], a close ally of Prime Minister Shinzo Abe, was to manage the preparation of the sites.

[34] The Japanese government gave Katō's private company, the National Congress of Industrial Heritage (産業遺産国民会議, NCIH), a budget of at least 1.35 billion yen.

Even before the opening of the first museum covering Hashima, Katō used part of her budget to publish a series of articles and videos that denied that Koreans were ever forced to labor on the island.

Shortly afterwards, the South Korean Ministry of Foreign Affairs officially strongly protested the interpretations of Hashima Island presented at the IHIC, which it characterised as revisionist.

The report stated that:[42][34] The oral testimonies displayed [in the centre], which were all related to Hashima Island, convey the message that there were no instances of [Koreans and others] being forced to work there.

Only one ethnic Korean had their testimony presented in the exhibit; he was a young child on the island and did not recall what the labor conditions were like or experiencing discrimination.

[34][44] Katō published a response on 4 August, in which she rejected the possibility of acknowledging that forced labor occurred, and claimed that "the people from the Korean Peninsula on Hashima Island [...] supported the system of increased production as a harmonious workforce like a family".

[46] Meanwhile, she had been conducting interviews with and inviting far right historical revisionists to visit her museum, such as Toshio Motoya, who denies that the Nanjing Massacre occurred.

She also appeared in an interview with Japan-based American influencer Kent Gilbert, who denies that Japan had sex slaves during World War II.

[35] Japan did not meet the deadline, and instead submitted a 577-page document defending the IHIC and saying its exhibits showed the complete history of the island.

[53] In 2009, the island was featured in History Channel's Life After People, first-season episode "The Bodies Left Behind" as an example of the decay of concrete buildings after only 35 years of abandonment.

[65] In Nintendo's third-person shooter series Splatoon, Hashima Island is presented partly as a stage you can battle on.