10 Great Wall of China Facts

The Great Wall of China--widely regarded as one of mankind's most impressive structures--draws 10 million tourists each year, notes ShanghaiFinance.com. For centuries, it has served as a beacon worldwide to people fascinated by its history and great length. Built initially as a military defense, it remains an iconic representation of China's culture and its people.

Construction History

China built the first sections of the Great Wall--corresponding to borders between states--during the Zhou Dynasty, which lasted from 1045 to 256 B.C. But these sections only became a unified line of defense during the reign of Emperor Qin Shihuang, between 247 and 221 B.C. The Wall has been under construction or experiencing maintenance ever since, ChinaHighlights.com points out. Construction on the parts left standing today occurred during the Ming Dynasty, from 1368 to 1644.

Length

As the Great Wall has gone through so many incarnations since its inception, calculating its exact length poses a challenge. Often called the "Ten-Thousand-Li-Long Wall," equal to 3,100 miles, modern estimates put the wall's length at 5,500 miles.

Builders

Millions of people--including criminals, soldiers and commoners--worked on the construction of the Great Wall over more than 1,000 years, according to the Travel China Guide website. Some saw it as part of their duty to their country; others saw it as a punishment. For all, it meant protecting and unifying their collective home.

Materials

Made of materials transportable over short distances from their origins to constructions sites, the Great Wall contains brick, stones, dirt, lime and wood.

Purpose

Built mainly as a military defense mechanism, the Great Wall also served as a symbol to unify the country in which it stands.

Location

It remains a source of contention exactly where the wall begins and ends, but it stretches west to east, roughly, from Kansu to the Yellow Sea. It crosses over 10 cities and provinces between these two points, with many sections open to visitors along the way, but the most popular opening exists in Badaling, reports ChinaTravel.com.

Preservation

Due to its age, natural forces and the military tactics that surrounded it for so long, much of the Great Wall has collapsed or fallen into disrepair. According to ShanghaiFinance.com, tourists and locals have also done significant damage to the wall.

Communication

Along the length of the wall, you can see many towers once used to communicate by fire and smoke. Due to the mountainous terrain along many parts of the wall, this was the most efficient means of communication for centuries, ShanghaiFinance.com says.

Visiting

The Great Wall remains a tourist attraction in all seasons, with the fewest tourists coming in the winter season, according to the Travel China Guide. The views surrounding the wall differ from season to season, with spring and summer offering an explosion of flowers and plants, and fall unveiling the changing colors of the leaves. The winter vistas of snow and ice lure some, but cold temperatures keep many away.

Seen from Space?

Many people once widely believed that, due to its great size and length, the Great Wall of China was the only man-made structure seen from space. Many astronauts have definitively said, though, that they could not see it from space, notes the Travel China Guide. It would only be possible if the entire wall were illuminated, as bright lights can be seen from space.