Beijing Temple of Heaven + Summer Palace + Yuanmingyuan Park 1-day tour [Professional guide, sincere service]

Located in the Temple of Heaven Park in Beijing, the Echo Wall is a circular wall of the Imperial Vault of Heaven, about 3.72 meters high, 0.9 meters thick, and 204.728 meters in circumference. The wall is made of Shandong Linqing bricks with polished joints, and is covered with blue glazed tile roofs. Because the wall has a very regular curvature and the wall surface is extremely smooth and neat, it becomes a good reflector of sound waves, which can be continuously reflected and propagated along the wall. If two people stand behind the east and west side halls, close to the wall, and one person speaks to the north, the sound waves will be refracted along the wall and reach the other side one or two hundred meters away. The two people talk and respond to each other, and the sound is long and interesting.