The Ming dynasty built the most extensive and best-preserved sections of the Great Wall.
The Ming dynasty ruled from 1368 to 1644 and expanded the northern frontier defences after repeated conflicts with Mongol groups, including the Oirats. Rather than being one continuous construction project, the Great Wall was a changing network of walls, trenches, watchtowers, passes and natural barriers built or repaired by many different states and dynasties.
Ming engineers often used bricks and dressed stone, especially near Beijing and other strategically important areas. These materials, along with substantial rebuilding and maintenance, helped many Ming sections survive in recognisable form. Famous visitor sites such as Badaling, Mutianyu and Jinshanling are largely Ming-era structures, although some stand on older foundations.
Earlier dynasties also made major contributions. Qin rulers linked earlier state walls, while Han governments extended frontier defences toward the west. The Tang and Han answers are therefore historically relevant, but the Ming dynasty is the canonical answer for the wall’s most extensive and best-preserved surviving sections.