The hippocampus is a part of the forebrain, locate in the medial temporal lobe. It belongs to the limbic system and plays major roles in short term memory and spatial navigation. Humans and other mammals have two hippocampi, one in each side of the brain. In rodents, where it has been studied most extensively, the hippocampus is shaped something like a banana. In humans, it has a curved and convoluted shape that reminded early anatomists of a seahorse. The name, in fact, derives from the Greek word for seahorse (Greek: hippos = horse, kampos = sea monster).