It is even better to say, if you are in the act of looking:

I am looking at the map to find out where the forest is.

it assumes you don't know where the forest is...hence why I am using the words find out.

Prepositions problem :/

What is the correct English sentence for "Miro en el mapa para saber dónde está el bosque"?

-I look at the map to know where is the forest.

-I look on the map to know where is the forest.


Thank you very much :)

It is more natural to say

I look at/in/into the map to find/see/ascertain where the forest is.

I look at the map to know where the forest is.