Noah's Ark

Noah's ark was no small chore to accomplish, especially because he undertook to do it all himself ("Build for you an ark …."). It's dimensions, in yards, were circa:

In length - 150 yards

In width - 25 yards

In height - 15 yards

To give you an idea of the real size of this boat, here's a very close approximation of it: Take a football field, and attach to it half of another football field (halved at the 50-yard line). The length and width of this extended field defines the floor of the ark. Then imagine you build a box on top of this area, with a height that's about as high a 3 goal posts one on top of the other.

At least he had 120 years (+ 7 days) to build it. [Rashi; Genesis 6,14]

(Why did G-d ask Noah to build the ark 120 years earlier? To raise the curiosity of by-passers who would ask, "What are you building?". Noah was then to answer, "G-d has decreed to destroy mankind by bringing a flood, because the people have transgressed by resorting to lewdness and robbery." And if they would ask, what wood are you using, he would say, "From the Gofer tree," and explain its significance: Making use of "Gofer" (can be rendered to mean "sulphur" in Hebrew) is another indication of pending destruction, implying it will be from the heat below. Just as their excessive transgressions have taken them to a state of lowliness, their destruction, too, will include a hot source from deep down.

After 120 years of such rumors in circulation, we can be sure the whole wide world in those days would have known and been forewarned about it. Because they ignored the warning and refused to mend their ways, the rest is history.

The additional 7 days [Genesis 7, 4] was to spare those mourning Metushelach the righteous, in whose honor the flood was delayed.)