If you go to the other end of the great crystal you will find some butt-stomping monsters, so there I guess (PROTIP: take lots of holy/curaja for those freaking undead that like to jump up under your feet every five steps when you're really close to Ultima ;ooo)

Oh man, Sagensyg, I'm getting mad just thinking about that part of the Henne mines. UGH. That was also difficult at a low-60s level >:[