The Henne Mines

The Henne Mines is a location in the land of Ivalice in Final Fantasy XII. It is an underground magicite mine explored by the Archadian Empire. At first only the Phase 1 site and dig are accessible, however after defeating at least 10 Espers, the Garif Geomancer will open up the gate to Phase 2 where the enemies become much tougher and the Esper Zodiark can be located and fought. Phase 2 can be accessed from the Feywood, but it's recommended that you wait to explore the area until your party's average level is reasonably high.

The Henne Mines are located just to the southwest of Jahara, and at first are only accessible via Chocobo through the Ozmone Plains. But when you completed the Draklor Laboratory, you could enter in the other side of the mines by going to the Feywood. but make sure your level is extremely high and above 70, because there is a lot of monsters that are tougher.

Monsters found here:

* Seeker
* Etém
* Hecteyes
* Jelly
* Nightmare
* Redmaw
* Tyranorox
* Thunderbug
* Abysteel
* Gizamaluk
* Necrofiend
* Glaring Eye (Rare)
* Melt (Rare)
* Ixtab (Mark)
* Mindflayer (Mark)
* Tiamat (Boss)
* Zodiark (Hidden Esper)

To see these monsters click here:
http://finalfantasy.wikia.com/wiki/Henne_Mines