In Japan, or perhaps more accurately just off the coast of it, there is an international airport which has been open for close to 30 years.
Millions of people use it every year and it's the closest international airport to the cities of Osaka, Kyoto and Kobe.
There's just one teeny tiny problem with this very busy and important airport - it's sinking into the sea.
Basically, the Kansai region of Japan was losing out on trade to Tokyo and it was decided that the place needed a bigger airport.
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However, with the existing airport surrounded by suburbs and with no room to expand, not to mention the noise complaints from locals, it was decided that the area needed a new airport altogether.
If there wasn't enough available land then they'd make some more, creating an artificial island to build the airport on.
Work to create this island started in 1987 and by 1994 the Kansai International Airport was ready to be opened.
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This artificial island proved it could survive natural disasters when Japan was struck by the Great Hanshin earthquake in 1995 and the airport was basically fine.
In 1998 it proved it could survive being hit by a typhoon as well, but nevertheless something rather worrying was happening.
Experts had factored in that the artificial island would start sinking as the weight of the airport would push down onto the soft soil of Osaka Bay, and reclaimed land is like a 'wet sponge' at first, but they'd expected it to sink by 5.7 metres by 1990 and instead it had gone down 8.2 metres.
Predictions had suggested that the island and airport would sink for a 50 year period before eventually settling at a safe level of 13 feet above sea level, but according to Smithsonian, the safe levels of sinking were reached in just a few years.
Extra money has been spent on a sea wall to protect the airport but some experts reckon the airport only has until 2056 before it sinks to sea level unless more can be done for it.
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One of the major problems is that different parts of the island are sinking at different rates, with the middle of the airport going down faster.
The overall cost of building the airport and keeping it from sinking too quickly is somewhere close to $20 billion (£15 billion), but since millions of people use it, the airport can't really be allowed to just sink into the sea.
Since construction it's sunk more than 11.5 metres in total, and the uneven nature of the sinking is dangerous for the building as well.
Still, the window of opportunity to do something remains, let's just hope we don't get to 2056 only to find everyone's been sitting on their hands.
Featured Image Credit: Hirotsuge Kurobe/Getty Tarohama/GettyTopics: World News, Science, Travel