Finding the kitchen refrigerator in the middle of a sleepless night or arriving at the home parking lot at the end of a daily drive are things that we mostly take for granted. However, such feats rely on complex brain computations that integrate multiple environmental and internal cues. Together these computations mediate the process referred to as spatial cognition, the study of which has been one of the most active research fields in modern neuroscience. In the early 1970s, John O'Keefe recorded the activity of individual cells in the hippocampus of a freely moving rat: he found cells that fired action potentials when the rat passed through a specific place in the environment. Examining the activity pattern of such 'place cells', he concluded that the hippocampus may contain a 'cognitive map' that represents the animal's location in its proximate environment. Since O'Keefe's seminal discovery about half a century ago, extensive research has led to a detailed characterization of hippocampal space processing in rats and other mammalian species.