Chinanews, Hohhot, May 9 - A cultural investigation team of famous Chinese archaeologists recently confirmed the two parallel ruins of the walls built some 2,100 years ago to be the northernmost section of the Great Wall in China.The two ruins are located 18 km from the border between China and the State of Mongolia, and expand to the territory of Mongolia. The interior wall is as tall as a six-storied building, while the exterior wall is a little taller. The top of the walls are 2.3 m wide, and the top part itself is 1.15 m tall.The walls were built of rocks from nearby places, and stuffed with sand. Long time of erosion has pushed the rocky part to slant to the middle. Several stone pits have been discovered in the mountains next to the walls.Not far from the walls, the ruins of a beacon tower were found, which was built with similar material and technology to the walls. Now, its southern wall has become a part of a cottage.