Where was the ark constructed? Who knows.......its just like the Garden of Eden........the entire earth's geology has changed from that before the flood event. They have even core drilled the An Artic Continent and found evidence of tropical plant life.
The Holy Scriptures clearly define the fact that the earth's topography and geography changed by God's command during the flood event.
God promised the waters of the earth would never again cover the entire globe because God changed the topography and geography of the earth.
NKJV (New King James Translation), "You (God) who laid the foundations of the earth, so that it should not be moved forever, You (God) covered it with a garment; the waters above the mountains (clearly there was not nor could ever be enough water to top such structures as Mt. Everest in the beginning); But......AT YOUR (GOD'S) REBUKE THEY (THE WATERS) FLED; at the sound of your thunder (sound of thunder...earthquakes, volcanos....etc), they (the waters of the earth) took flight, they hastened away.(where did they go? to the 7 mile deep trenches found to exist in both main oceans), they (the waters) went up over the mountains; they went down into the valleys, to the place You (God) founded (made) for them (God made the valleys sink and the mountains rise....creating new mountains ranges such as Mt. Everest and new ocean floors such as the Mariana, the Challenger Deep, The Tonga Trench, Galathea Trench....etc.)
It concludes with ".........You (God) set a boundary that they may not pass, so that they may not cover the earth" -- Ps.104:5-9
Thus the covenant of the Rainbow........a token sign from God to never cover the earth in water again. (Genesis 9:15-18)
Science proves that at one point in earth's history all the land masses were made up into one great continent called Pangaea. The continental drift theory. The only difference in the history is the outrages time period claimed by conjecture, speculation and assumption.