In the past decade, research on the hippocampus and navigation has made significant strides. Recent studies have elucidated the specific neural mechanisms underlying various functions of the hippocampus, such as memory formation, spatial navigation, emotional regulation, learning, and neurogenesis. A multitude of techniques, such as brain imaging, optogenetics, calcium imaging, and virtual reality, have been employed to probe these mechanisms in both animals and humans. Recent studies have also addressed the question of how the hippocampus integrates spatial information with other cognitive processes, such as memory and decision-making, to support goal-directed navigation. This interdisciplinary approach has broadened our understanding of the role of the hippocampus in tasks that go beyond traditional spatial navigation. In this book, we wish to provide a state-of-the-art overview of the hippocampal functions and diseases that affect them such as Alzheimer’s disease, temporal lobe epilepsy, stroke, hypoxia/anoxia, depression, schizophrenia, post-traumatic stress, and aging. Addressing the underlying causes and providing appropriate treatments can help manage symptoms and improve hippocampal functions in many of these pathologies.