BEIJING, July 14 (Xinhua) -- China's Great Wall was originally built to keep out invaders. Today it is arguably the main attraction bringing foreigners into the country.
The 6,700 kilometer-long wall stretches from the east to the west of north China, through five provinces. The Beijing section was mainly constructed during the Ming Dynasty (1368-1644), and is considered the most frequented and best preserved part of the Wall.
There is more than one section worth exploring. Here is Xinhua's list of the highly recommended sections.
Badaling
Badaling boasts the best-preserved and most imposing section of the Wall, frequently portrayed in guide books and on postcards.
The section, which winds up and down the Jundu Mountains in Yanqing county, is made of large blue bricks and averages about 7.8 meters high. At regular intervals are window embrasures and castellated crenels. Beacon towers, originally for relaying military information, offer a respite from the weather at fixed intervals.
Climbing the Great Wall can be tiring, but the views are rewarding.
Cable cars are available.

Location: In Yanqing county, to the northwest of downtown Beijing
Route: Take bus No.919 from Deshengmen Long Distance Bus Station, 500 meters east of Jishuitan Subway Station. Buses depart every half hour from 5:50 a.m. and return from Badaling until 6:30p.m.. The trip takes one to two hours.
Phone: 6912-1737
Ticket: 45 yuan (6.5 U.S. dollars) per person
Mutianyu
The Mutianyu section stretches about 2,250 meters and is ranked among Beijing's 16 recommended scenic spots. It's unique due to the great crenels on both sides of the walls. It's steep mountains and picturesque forests make it one of the most scenic sections. Cable cars are available.

Location: In Mutianyu village, Huairou District, about 45 miles to the north of downtown Beijing.
Route: Take bus No.916 at Dongzhimen Long distance Bus Station,100 meters east of Dongzhimen Subway Station Exit D, then walk 150meters to the left. Buses depart from 5:20 a.m. and return until 6:30 p.m. The trip takes two to three hours.
Phone: 6162-6505
Ticket: 40 yuan (5.8 U.S. dollars) per person
Simatai
This section of the Wall is regarded as the essence of the Great Wall built in Ming Dynasty in Beijing. Off the beaten path, it is a good choice for outdoors types and hikers. It features 15 watchtowers in various shapes and styles. You may be physically challenged even if you are energetic and experienced.

Location: Gubeikou Town, Miyun County, to the northeast of downtown Beijing
Route: Take bus No.980 at Dongzhimen Long distance Bus Station,100 meters east of Dongzhimen Subway Station Exit D, then walk 150meters to the left. Buses depart from 6 a.m. and return until 7 p.m. The trip takes two to three hours.
Phone: 6903-1051
Ticket: 40 yuan (5.8 U.S. dollars) per person
Accommodation: If you want to stay overnight, there is a hotel just at the foot of Simatai which accommodates up to 80 people. Each room has three beds and costs 260 yuan. A reservation is recommended. Telephone: 6903-5159