China has a $8,500,000,000 bridge that's 102 miles long and conspiracy theorists are obsessed with it

China is home to the world's longest bridge, spanning 102 miles, which conspiracy theorists happen to be obsessed with.

We all know by now that the country is no stranger to mammoth projects, whether that's a hydropower plant so powerful it's slowing the Earth's rotation, or the planet's most expensive megaproject.

Back in 2011, China unveiled the Danyang–Kunshan Grand Bridge, which took four years and 10,000 workers to build.

The Danyang–Kunshan Grand Bridge (Edward L. Zhao/Getty Images)

It currently holds the Guinness world record for the world's longest bridge at around 102 miles long - or 538,560 feet. That's the length of almost 90 Brooklyn Bridges end-to-end, for some context.

Costing around $8.5 billion, the structure is part of the Beijing-Shanghai High-Speed Railway and links the cities of Shanghai and Nanjing.

Commute times between the two locations were cut from around four and a half hours to just two once the bridge was operational.

The Danyang–Kunshan Grand Bridge, roughly 31 meters off the ground, signified a major engineering milestone for the country. Constructing a bridge of such scale would've been no mean feat, especially when you consider the challenge of building it across varying terrain.

The bridge crosses low rice paddies, densely populated cities, sections of the Yangtze River Delta and a few miles of open water across the Yangcheng Lake in Suzhou.

The bridge cut commute times from four and a half hours to just two (LUPOO/ullstein bild via Getty Images)

It's also been reinforced to withstand natural disasters - including earthquakes and typhoons - as well as hits from naval vessels that weigh up to 300,000 tons.

Like all good things, though, it soon became victim to the swirling vortex of disinformation that is the internet.

Danyang–Kunshan has been widely - and wrongly - cited by flat Earth conspiracy theorists online.

Once-viral posts claim the bridge is completely straight, with 'no curve' which people say 'proves' the Earth must be flat.

Theorists go on to share photos of the bridge - or sometimes, totally different bridges - from unusual angles in an attempt to create evidence to support their claim.

Flat earth conspiracy theorists are obsessed with the world's longest bridge (Adastra/Getty Images)

Those who believe the Earth is round have fought back online to disprove the theories, showing how even a pool cue that appears curved from one angle can look completely straight from another.

Elsewhere, Mechanical Engineering wrote: "It would have been difficult enough to build a straight road of over 100 miles in length so you can imagine the curvature of the Danyang Kunshan Grand Bridge.

"The journey of the bridge takes in canals, rivers, lowland rice paddies, lakes and uneven terrain as well as major towns and cities.

"It is difficult to understand how engineers were able to design such a phenomenon which undulates to such a degree."