Whilst tunnels have been made for as long as there have been ways to burrow and move earth, modern construction techniques using drills, dynamite and conveyor belts roughly date back to the mid-19th century.

The first tunnel project as we recognise it today, the Thames Tunnel by Marc and Isambard Kingdom Brunel, was the first underwater tunnel in the world, only made possible through the use of a pioneering tunnelling shield that would later inspire the tunnel boring machine.

It took 18 years, a father-son team of two of the greatest civil engineers in British history and a tunnelling system that had never been used before in order to create it.

Nearly 3000 years before this, however, one of the first cities in the world allegedly attempted to undertake a similarly astonishing feat of engineering without anything like the technology available.

In order to understand this tunnel and what we can learn from it, we need to sort out fact from myth in one of the most mysterious cities in human history.

The Sunken Tunnels Of Babylon

Located 50 miles south of Baghdad in what is modern-day Iraq, Babylon was one of the most influential cultural and political capital cities of the ancient world, remaining the subject of wonder, study, speculation and a nexus point where mythological fiction meets fact.

It is perhaps best known for the Hanging Gardens, one of the Seven Wonders of the Ancient World, which was either destroyed without a single trace, never existed or was based in a different city entirely.

The river that allegedly made this possible, the Euphrates, split Babylon into two roughly equal parts, but whilst ferries were the main form of crossing across the 929-metre stretch, according to ancient historians, there was also a vast tunnel large enough for chariots to ride through that linked a temple on one side with the royal palace.

If it had existed, it would have not only been the first ever underwater tunnel, but the only one attempted for thousands of years until the Brunels in London.

How Was It Allegedly Constructed?

There are two main historical accounts that describe the tunnel; they are Bibliotheca Historica by Diodorus in around 50 BC and The Life of Apollonius of Tyana by Philostratus in the third century AD.

Whilst the accounts vary on the details, it is alleged to have been 15 feet wide, 12 feet high and 929 metres long, created by diverting the waters of the river and using a primitive form of the cut and cover tunnel-making technique.

It was lined with brick and waterproofed with bitumen glue and asphalt, which would have been found in the Middle East even several thousand years ago. It also allegedly had two gates made of bronze on either end of the tunnel.

It was completed in 260 days, an astonishingly rapid turnaround for a tunnel of that scale. For comparison, the Thames Tunnel is half the length but took 18 years to make, whilst the Elbe Tunnel similarly took four years to build in 1911.

Was It Real And What Can We Learn From It?

Babylon was built as much on a foundation of mythology as it was on bitumen, and because of this, it is remarkably difficult to ascertain with any degree of certainty the extent to which it actually existed.

What does not help this in the slightest is damage and destruction of the ruins as a result of the Iraq War in the 21st century, which has made it much harder for archaeologists to make a determination.

One common date given for its construction, between 2180 and 2160 BC, is impossible, given that Babylon itself was only founded as a small village circa 1894 BC.

Philostratus credits its construction to a “Queen Medea”, whose name does not match those of any known historical queen, whilst Diodorus credits it to the semi-mythical queen Semiramis.

She was based on Queen Shammuramat, who reigned between 811 and 806 BC in mysterious circumstances that are still the focus of intense debate to this day.

There is no verifiable physical evidence of a tunnel at all under the Euphrates, which does not necessarily rule out that one existed but was destroyed over time after Babylon was abandoned, but also does not provide concrete proof.

At the same time, it used techniques and materials that were thousands of years ahead of its time, at least in terms of tunnel construction, as told in accounts that date back to when the city at least existed, so it languishes in the same gulf between fantasy and fact as the Hanging Gardens.