I was reading a history book on the topic of Robin Hood and the following line was in it:
Robin Hood lebte im Sherwoodwald
Now, I know that this sentence translates to roughly
Robin Hood lived in Sherwood Forest.
but I also know that im = in dem
so to me, the sentence translates better as
Robin Hood lived in the Sherwood Forest
My question is, why is the definite article needed in this instance?