Introduction to the ancient plank road ruins: At the Languan Ancient Road site, you can see the traces of the plank road built by the ancients on the steep cliffs. There are still square holes on the cliffs beside the road where wooden beams were inserted into the ancient plank road. Each hole has 30 Centimeter square, some holes still have broken wooden beam roots. As time goes by, this ancient plank road was the main road from Chang'an to the south.