Read this: Transport in the Republic of the Congo includes land, air and water transportation. The country's rail system was built by forced laborers during the 1930s and largely remains in operation. There are also over 1000 km of paved roads and two major international airports (Maya-Maya Airport and Pointe Noire Airport) which have flights to Paris and many African cities. The country also has a large port on the Atlantic Ocean at Pointe-Noire and others along the Congo River at Brazzaville and Impfondo.

When was the Congo's train system built?
What is the answer? (If it cannot be answered, return "unanswerable")
1930s