After the part with the ancient cave, there is a cave near some mountains. As soon as you go in, there is a save pool and healing spring on the sides and a person blocking the doorway up ahead (6-8 steps from entrance). When you talk to him, he says that I cannot pass until an investigation team comes back. Where are they

Usually in spots in the game like that, you have yet to do something else in the game. If I am thinking about the right place, you might be about 2 or 3 dungeons away from the point of the game. But I'm not sure. Can't get at my Game Boy for another 2 days.