2. Great Wall of China
Image Source: Keith Roper
The word “great” is definitely not an exaggeration in this particular case. Construction of the Great Wall was started in the year 475 B.C. and was intended to protect China from the marauding Huns. It was worked on for an incredible 2,000 years as different sections were built, re-built and merged to create the wall as it stands today. The wall stretches for a mind-boggling 5,500 miles which is some 2,500 more than the distance between New York City and Los Angeles.
