Sniffing
The Murial collapsed completely, burying the only piece of history with it. Fortunately, Shen Yu made a small mountain underneath which covered the hollow area; otherwise, the whole Senter Valley Base would have collapsed with it.
After seeing that through, he disappeared from there and appeared high above the Senter Valley, looking solemnly at the towering Wall of Darkness. Except, the wall was actually solid.
At first, Shen Yu had not thought much about the Hollow Mountains as it was the Xianxia World and things like it were common.
But after going through the memories and knowing what the Hollow Mountains were, he grew suspicious of them. However, he did nothing as it was not related to him.
Until today.
After learning that the Hollow Mountains were created after the major calamity of fifty thousand years ago, he had a guess that they were somehow related.