At the end of the 2nd century, Bulgaria became independent and Dingdu Ternovo was due to its dangerous position. The palace was built on the top of Mount Charevitz and Mount Trapeziza, built high walls to surround it, and set up the Royal Forest Army to guard. The river of the Yangtra between the two mountains is clear and clear, nourishing all beings and seedlings, and constantly extending the foundation of the royal industry for two hundred years, its scale and prosperity second only to Constantinople. At the end of the 14th century, Ottoman iron and cutters broke through heavy walls and split the strong mountain gates, and the century-old dynasty was drowned in bloody rubble and fell apart. Now, standing on the ruins of the ancient city palace overlooking the wall, the sunset "outside the mountain green mountain building", "the green mountain is still there, a few degrees of sunset red".