Monster Hunter 3 (tri) - Volcano Map Glitch
EDIT: To prevent further asspain, we were not the ones to find this glitch. We heard a rumor that this would work and we put it to the test, we're not "copying" anything. Chillax.
Now this is really cool, it's something my girlfriend and her friends tried after hearing about it from someone, I can't believe it worked.
Basically you jump off the cliff in area 10, and have a Gunner shoot Pellet S at you as you fall down into area 5. If you do it correctly, you'll fly out of the map and be free to explore stuff from behind the scenes.
A huge thanks to my girlfriend and her fine friends for recording this video!