Your team must cut out and assemble the tower.
Read the message you see in the round windows: “Letter A=3”
This means you need to create an alphabet cipher, where A=3, B=4, C=5, and so on through all the letters of the alphabet.
Now write out all the numbers in the remaining arched windows. Use your new fancy schmancy alphabet cipher to translate these numbers back into letters. This will give you the Puzzle Answer!