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).
Quick Answer. The main Great Wall of China stretches approximately 5,500 miles along the southern edge of Inner Mongolia. Explorer experts state that it takes 18 months to walk its entire length. It was constructed during the Ming dynasty in the 14th and 15th century, and is sometimes called the Ming Wall. Continue Reading.