After the flood God asked Noah to build another Ark.
"Noah, I want you to build another Ark", God said.
"What!?" said Noah - "You promised you wouldn't flood the earth again"
"That is true", said God, "And I will keep that promise, but the fish complained that they missed out when I called the animals into the Ark."
"But the fish didn't need to go in the Ark.", said Noah, "They live in the water!"
"I know that", said God, "but fish are pretty dumb. I managed to convince them all that they didn't need to go in the Ark - all that is, except the Carp - they just didn't get it. So, to keep them happy, I told them you would build an Ark for them."
"OK", said Noah, "so just a little Ark for 2 of the Carp?"
"No", said God, "I promised you would save them all, so I want you to build a large Ark, 100 Cubits long and 50 Cubits wide with 5 decks of aquariums for the Carp."
And so it was that Noah built the World's first Multi-story Carp-Ark!