After they heard Eira's words, many different thoughts began to cook up in their mind. Even though this place looks like a fencing surrounding something at the other side, they didn't know what they guessed was true or not.
Maybe this place was a natural occurence of this miraculous mountain range. Maybe these trees were supposed to grow like this, by arraying themselves very close to each other..... These would be the first kind of conjecture anyone would speculate in this kind of situation. And Ashmus and others also did.
But.... if these possibilities were not true and some powerful individual had deliberately created this place then what is that being made this place for. What is he trying to hide from the rest of the world? Could that powerful individual be a magical beast or human or maybe some other creature?