In the Bible, God tells Noah he has to build an ark and load a pair of every kind of animal before a great flood engulfs the world. It is widely regarded as a myth, but could it actually be true?
By Jeremy Bowen
Presenter, Noah's Ark
The story of Noah and his ark is one which sticks in the minds of children and never gets forgotten.
God warned Noah - the only good man left in a world full of corruption and violence - to prepare for a great flood. With his sons he built a great ark and the animals marched in two by two. By the time the rain started to fall, Noah was ready. The ark was a refuge until the waters went down, leaving Noah and his menagerie high and dry on Mount Ararat.
There are many problems with the story. If the story is taken literally, it would have taken 35 years for Noah and his family to load two of every animal on earth. And a flood that engulfed the Earth would have left a signature for geologists - yet none has been found.
But it is possible to build a much more credible version of the story based on a different reading of the Bible, on ancient Babylonian sources that predate the Book of Genesis, and on archaeology and science.
The traditional shape of Noah's Ark comes from the imaginations of 19th Century artists. It would have been about 450ft long, and experts say it would have broken apart.
Even if such a feat of marine engineering had been possible, there are about 30 million species of animals in the world. For so many creatures, a fleet of enormous arks would have been needed.
Geologists have also proved that there is not enough water in the world to cover all the continents, then or now.
But just because the details of this familiar story do not add up, should we turn our backs on Noah and the ark?
Loading 30 million species of animal would have taken 35 years
We have to forget the idea that such a huge boat carrying all known animals existed, that it came to rest on Mount Ararat in modern-day Turkey, and that a flood covered the entire Earth.
In 1851, British archaeologists discovered hundreds of clay tablets while digging in ancient Babylon.
It was 20 years later that British Museum assistant George Smith became the first person to read them. He found the story of Gilgamesh, which bore strong similarities to that of Noah. He was visited by the great gods, who decided there would be a great deluge, told him to make a boat and carry in it the seed of all living things.
Further Iraqi texts were discovered, showing the story emerged in Mesopotamia. And in the 1930s conclusive evidence of a huge flood in the area about 5,000 years ago - the time of the story of Noah - was found.
What we know of the culture of what is now Iraq gives the first glimpse of the real-life historical figure behind the myth.
Noah might have been king of a city called Shuruppak. He would have had a kilt, a shaven head and eye make-up, like the figures portrayed in artworks created in what was then known as Sumeria.
The epic of Gilgamesh says Noah had silver and gold, then the currency of wealthy merchants, suggesting he was a businessman.
Instead of building an ark to survive a great flood, he is more likely to have built boats to trade goods like beer, grain and animals.
All the big trading centres of the era were on the River Euphrates and it was cheaper to move goods by water than land. Sumerians were able to build barges about 20ft in length, and marine archaeologists have not found remains or inscriptions of larger vessels.
But they believe they would have had the technology to have built a series of barges and used them like pontoons on which a much larger boat, or ark, could have been constructed.
Parts of the Euphrates were only navigable at certain times of the year, when the waters were deep enough for large boats.
Noah was likely to have waited for the melt waters to arrive in June and July and, if these had combined with a tropical storm, the river could have flooded the Mesopotamian plain.
The currents in the area would not have taken him towards Mount Ararat, but out into the Persian Gulf. Life would have been difficult, but they could have survived on the animals and beer on board.
One Babylonian text suggests the ark came to rest on what is now the island of Bahrain, providing a very different yet plausible end to the adventure.
Could this story have provided the inspiration for the holy men who wrote the Book of Genesis 2,000 years later? When they first heard the story, how could they fail to recognise its moral power, that if humankind falls short of God's laws, there's a dreadful price to pay. Behind that moral message lies one of the world's greatest stories.
And behind that story we can just glimpse a real man, a real boat and a real adventure.
Noah's Ark will be broadcast in the UK on BBC One on Sunday 21 March at 1900 GMT.