HERE IS A CLAY TABLET explaining Noah's Ark was Round. This is 4,000 years old. I found it on Mysterious Places, Beings, Structures, Artifacts & Images of the world on Facebook.
THE CIRCULAR ARK OF ATRAMHASIS (NOAH).

A written tablet which is about 4,000 years old and was found in the Middle East during the 1940s by an RAF Pilot, Leonard Simmons, was passed down to his son Douglas, who decided to take it to the British Museum to be deciphered.

Douglas took it to Irving Finkel, an expert at the British Museum, who "took one look at it an nearly fell off his chair". He then translated the 60 lines of script, and believes it is one of the first tablets to describe the shape of the famous Ark, due to an "instruction manual for building an Ark and its precise measurements" written on the tablet. Dr Irving Finkel, who is the world’s foremost expert on ancient Sumerian and Babylonian languages, says it sheds new light on the iconic biblical tale of Noah's Ark, over a thousand years before the Biblical texts.

Having spent 20 years translating the tablet Dr Finkel, said. "But the Ark didn't have to go anywhere, it just had to float, and the instructions are for a type of craft which they knew very well. It's still sometimes used in Iran and Iraq today, a type of round Coracle which they would have known exactly how to use to transport animals across a river or floods, until the floodwaters retreated.

On the tablet, It says that the God spoke to Atramhasis, a Sumerian king who is the Noah figure in early versions of the Ark story. So the God must have been Enki.

The tablet's translation says: "Wall, wall! Reed wall, reed wall! Atramhasis, pay heed to my advice, that you may live forever! Destroy your house, build a boat, despise possessions And save life! Draw out the boat that you will build with a circular design, Let its length and breadth be the same."

Mr Finkel, the curator of the recent British exhibition on ancient Babylon, believes it was during the Babylonian captivity that the exiled Jews learned of the story of Atramhasis (Noah) and incorporated it into the Old Testament.

The Enuma Elish names the hero of the flood as Ziusudra not Atramhasis, or they are one and the same. Other versions report his name as Ubar-Tutu. After some translations, editing, and embellishment, it was changed to Utnapishtim in a more detailed account in the Epic of Gilgamesh. After at least 1,000 generations of further translation, interpretation, and some enthusiastic exaggeration into the Hebrew version, the name was finally changed to Noah.

http://www.theguardian.com/culture/2014/jan/24/babylonian-tablet-noah-ark-constructed-british-museum

http://en.wikipedia.org/wiki/Atra-Hasis