The Great Wall of China
The Great Wall of China is a vast wall which extends along large parts of the northern border of modern-day China, particularly along the border with Mongolia.
It was built in many stages. The earliest fortifications were built as early as the seventh century BC, but it was around 200 BC when these fortifications started to be joined together to form a wall. The wall is not continuous and large parts of it no longer survive today.
It was built intermittently by various Chinese rulers to try to protect certain parts of northern China from raids by people from the Asian Steppes and Mongolia who were seeking to raid into China to capture its wealth.
In total it spanned over 20,000 kilometres, making it one of the most extensive building projects ever undertaken.
Unfortunately, much of the wall has eroded or has been destroyed in wars over the centuries. However, large sections of the wall still survive and in 1987 the Great Wall was made a UNESCO World Heritage Site.