Niger plains References Niger plains plains, Africa Ask Anything Homework Help Written by The Information Architects of Encyclopaedia Britannica The Information Architects maintain a master list of the topics included in the corpus of Encyclopædia Britannica, and create and manage the relationships between them. The Information Architects of Encyclopaedia Britannica Britannica AI Ask Anything Learn about this topic in these articles: Benin/ ReliefThe Niger plains, in the northeast of Benin, slope down to the Niger River valley. They consist of clayey sandstones. Read MoreThe Niger plains, in the northeast of Benin, slope down to the Niger River valley. They consist of clayey sandstones. Read More