im assuming that the meteor has something to do with itI found three things on Jailbreak:
1. There appears to be a hole where a waterfall spills out near the gun store. As you swim up there is a large pocket in the middle of the waterfall with nothing inside...
2. The river where the main waterfall is at, has a large jagged brick wall. There is another brick wall near that area where the train station is at.
3. I'm pretty sure everyone knows this one, the ice cave at the top of the mountain that cannot be entered through.
I'm more concerned about those brick walls outside. My theory is there is a sort of tunnel-maze that you have to go through. And in the previous clue from yesterday where it mentioned you must "infiltrate this place without harm". Meaning you must find your way through the maze without going the wrong way that will lead to your death.