Quiz: Remember the definition of mal de mer?
seven cataracts in the Lualaba River, central Congo (Kinshasa). The falls extend for 60 miles (100 km) along a curve of the river between Ubundu and Kisangani. The total fall in the river's elevation is about 200 feet (60 m), and the seventh and largest cataract is 800 yards (730 m) wide. Beyond the cataract the Lualaba becomes the Congo River. A rail line goes around the falls, connecting river ports at Kisangani and Ubundu.