Which of these was a Scottish explorer of the African continent and is credited as being the first Westerner to encounter the Niger River?
Leif Ericson, a Norse explorer regarded as the first European to land in North America before Christopher Columbus, established a settlement at Vinland, which has been tentatively identified as being where?
One of the longest African rivers is also recorded as the world's deepest. What is the measured depth in parts of the river?
