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).
To protect against harassment by the Hun aristocrats, Emperor Qin Shihuang ordered the Great Wall be built. He command MengTian general and thousands upon thousands people to build the new city wall, it stretch more than five thousand kilometre in an unbroken chain. Ruins of Qin Shi Huang Great Wall at Inner Mongolia.