The United States and Japan are developing research submersible systems that will be able to explore the ocean floor's deepest spot: the 10,920-m Challenger Deep at the southern end of the Marianas Trench off the Mariana Islands. Sketch of the Shinkai 6500, a
Construction Time of the the Ming Wall. The Great Wall at Badaling. Over 2,000 years, many imperial dynasties and kingdoms built, rebuilt, and extended walls many times that subsequently eroded. The latest imperial construction was performed by the Ming Dynasty (1368â1644), and the length was then over 6,000 kilometers (3,700 miles).
All About the Great Wall of China. The Great Wall of China was built over 2,000 years ago, by Qin Shi Huangdi, the first emperor of China during the Qin (Ch'in) Dynasty (221 B.C - 206 B.C.). In Chinese the wall is called Wan-Li Qang-Qeng which means 10,000-Li Long Wall (10,000 Li = about 5,000 km).