The hippocampus's a major component of the brains of humans and other mammals. It belongs to the limbic system and plays important roles in long term memory and spatial navigation. Like the cerebral cortex, with which it's closely associated, it's a paired structure, with mirror-image halves in the left and right sides of the brain. In humans and other primates, the hippocampus's located inside the medial temporal lobe, beneath the cortical surface. Its curved shape reminded early anatomists of… (More on Hippocampus)