万里长城 - The Great Wall
The Great Wall is a Chinese fortification begun around 220 BC then expanded to its present length of 6,300 km in the 14th to 17th centuries by the Ming Empire to protect itself from raids by Mongol and other nomadic tribes. I visited on a cold spring day, following a trip to the Ming Tombs which is equally impressive - 500,000 men over 25 years to build the crypt only discovered in the latter half of the 20th century.
The Mao expression on the oblix next to me says loosely: 'one cannot know China without visiting the Great Wall.'