After you complete the Forest Temple the twilight is no longer in that region and Link must travel to the next region of Hyrule to rid it of the twilight
The big key
get the boomerang.
as soon as you defeat the Minny Boss in the Forest Temple you get the boomerang
In Twilight Princess, the only monkey whose name is given is the forest temple boss monkey - his name is Ook.
collect all the monkeys then defeat the flower boss
Mainly by usingyour boomerang you havereceived in the Forest temple by beating the monkey. (miniboss)
It's in the Forest Temple (1st Dungeon. You need to beet Ook to get it though.
In the first temple
go to the woods near the forest temple to go to the secret grove........ again
do a z like this gate 1----------2 3----------4
Death Mountain
the forest temple