Truth behind $400,000,000 American bridge that's left people mesmerized after 'vanishing into water'

A US bridge which sees vehicles seemingly vanish into thin air has left social media users dumbfounded.

We see all sorts of random videos whenever we open up our phones.

From dancing pets to stunning biological simulations, we never know what we're going to get.

But seeing a bunch of cars appear to drive into the ocean and disappear? That was not on my bingo card.

One viral video showing exactly that has been doing the rounds on X, formerly Twitter, recently.

Racking up millions of views, the videe gives an aerial view of cars driving down a bridge in the middle of a body of water, before they vanish into seemingly thin air.

But what exactly is it?

What is the viral video really showing?

No, the unusual video isn't the work of AI.

Instead, it's actually the Monitor Merrimac Memorial Bridge Tunnel, or MMMBT for short.

Located in Hampton Roads, Virginia, the 4.6 mile (7.4 km) structure connects the cities of Newport News and Suffolk, while impressively crossing three major rivers; the James, Nansemond and Elizabeth.

The entire structure includes 3.2 miles of twin trestle - two side-by-side elevated roadways - two artificial islands and a tunnel which, on its own, is 4,800 feet (1,500 m) long.

So no, sadly, the vehicles aren't disappearing into some kind of magical portal, or into the depths of the sea. They're heading into an underwater tunnel, creating a pretty cool optical illusion.

The MMMBT was erected 33 years ago, in April 1992, and cost around $400 million to build.

It's named after the USS Monitor and CSS Virginia (formerly Merrimack), the first ironclad warships to face off in battle.

The Battle of Hampton Roads, from March 8 to 9, 1862, took place within a mile of the bridge-tunnel.

Why was the MMMBT created?

The MMMBT has helped with a number of issues, including traffic congestion and national security.

Its tunnel section allows large naval and commercial ships to pass overhead without obstruction - a crucial aspect when building a bridge on one of the busiest shipping lanes on the US east coast.

Engineers could've opted for a tall bridge instead, but that could have been dangerous for both the ships passing under and the fact it would be vulnerable to severe weather or attacks.

The area is home to major military installations, like Naval Station Norfolk, so having a tunnel instead of a large bridge reduces the vulnerability of key infrastructure to both those risks.

Then there's use of trestles and artificial islands.

These helped engineers adapt to the region’s complex geography and water depths, what with it crossing three major rivers and all that!

What people have said about the viral video

Plenty of social media users were amazed by the video, with others asking people to explain what it was showing.

Others, however, knew what it was right away.

Responding to the video, one person wrote: "That is a tunnel. Welcome to your first day of elementary school," as a second piped up: "That’s called a tunnel my friend."

"Open the schools," a third quipped.

Others were left in awe by the structure, as one person penned: "Appreciate engineers!"