The vast, low-lying central area is a basin-shaped plateau sloping toward the west and covered by tropical rainforest. This area is surrounded by mountainous terraces in the west, plateaus merging into savannas in the south and southwest, and dense grasslands extending beyond the Congo River in the north. High mountains are found in the extreme eastern region. | The vast, low-lying central area is a basin-shaped plateau sloping toward the west and covered by tropical rainforest. This area is surrounded by mountainous terraces in the west, plateaus merging into savannas in the south and southwest, and dense grasslands extending beyond the Congo River in the north. High mountains are found in the extreme eastern region. |