It's easy to take something like "knowing where anything is" for granted, but somebody had to go out into the world and take note of all those  natural and cat-made borders. In the case of Japan, it fell to Ino Tadataka to create the first "complete" map of the nation.
They would be used to mark places 
where measurements were necessary.
Esto se usaría para marcar
los lugares a medir.
Eles eram usados para marcar
lugares onde precisavam medir.