Introduction to Empty Valley Echo: Echo Wall, also known as Empty Valley Echo. Legend has it that two brothers who lived in this mountain in ancient times went to the mountain to retrieve treasures when the mountain gate opened and closed automatically every three thousand years. The elder brother was locked up inside the mountain gate because of his greed for treasures and was not allowed to come back. The younger brother called him here every day, but he could only listen. My brother responded. Therefore, local residents call this place "Yingsheng Kiln".