1. Forest Temple
2. Goron Mines
3. Lakebed Temple
4. Arbiter's Grounds
5. Snowpeak Ruins
6. Temple of Time
7. City in the Sky
8. Palace of Twilight
9. Hyrule Castle
the forest temple
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
In the Forest Temple, the very first one. If you want to know exactly where they are in the temple, walkthroughs are very helpful.
When you get compass it will tell you the location of the monkeys
Death Mountain
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
It's on the map.
beat the boss
If its the Baboon Ook, then he is the Mini-Boss in Forest Temple.
get the boomerang.
The big key