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).
Below we give you the background behind the figures, explaining what is counted as the Great Wall, and how the length of the Great Wall has changed through different dynasties. The Official Length: 21,196 km (13,170 mi) After a five-year-long survey, the total length of the Great Wall was measured. On June 5th, 2012, the State Administration of Cultural Heritage announced that the official length of the Great Wall is 21,196.18 km (13,170.7 mi). This is the first time that China has scientifically and systematically measured the length of the Great Wall. It's a misleading figure as some sections of different eras were built on top of or right next to each other.