In the west-central African country of the Republic of Congo, Mayombe is a name that inspires both love and hate in local residents.

Mayombe is a vast expanse of virgin forest with more than 300 kinds of plants. For Congo, one of the world's most undeveloped nations, the Mayombe, with rich reserves of nature resources and wood, is a national treasure.

However, the ancient forest lies between Brazzaville, the nation's capital city, and its second-largest port city, Pointe-Noire. Out of repair for years, the old national road, which once linked the two cities, has been submerged under forest growth and rainwater.

Connecting the country's political center to its economic hub is a dream of the Congolese.

When staff of China State Construction Engineering Corp, the world's largest construction contractor by revenue, arrived in 2008, it was time for the Congolese people to make their dream come true.

"Get through the Mayombe forest, and we will achieve success and honor," said Li Jiqin, general manager of the CSCEC overseas business department, in May 2008 during the ceremony that launched the Congo National No 1 Road project.

Negotiated during the Forum on China-Africa Cooperation in 2006, the Congo National No 1 Road project was the biggest infrastructure contract signed between the two countries that year.

With a total length of 580 kilometers, the road will connect the capital city, the second-largest port city, the third-largest city and many other cities and towns.

Once construction is completed, the road will benefit more than 65 percent of Congo's total population of 4.2 million.

The 164-km first phase of the project is finished, and the road was opened to traffic in October 2011.

"Go forward, go forward, Chinese people are making history in Mayombe." That's the faith that encouraged and strengthened the determination of each Chinese worker to build a high-quality transportation lifeline in the dangerous area.

Of the more than 1,000 Chinese builders on the construction team, more than 800 were infected with tropical illnesses in various degrees, including malaria, typhotoxin, filariasis and dengue fever.

Unknown kinds of worms and snakes have been a severe threat to Chinese workers' health and safety. Even pythons and crocodiles waited underbrush and in rivers.

The area has a rainy season of more than six months, so the construction period is only six months. When the rainstorms come, the road instantly turns into a mess of swamps, rivers, mud and potholes.

However, none of the Chinese staff retreated. In the Mayombe area, estate owners and local people all became accustomed to the scene of tireless Chinese builders working all night with lights blazing, and with machines operating day and night.