i am building one as a map well 2 in total but i am on the first one and i don't know how many blocks they are
I do believe you can world download the map, if it helps to build a map, only for the dimensions. But you cannot use the map for public use.
after about 45 minutes if they are a perfect square shape they are 48 by 48 in length and width i have no clue how tall the are tho