The ability to map space is critical to survival. In mammals, space is mapped by neural networks in the hippocampus and the entorhinal cortex. These brain areas contain specialized position-coding cell types, including grid cells, which are active only when animals are at locations that tile environments in a periodic hexagonal pattern. I will first show how space is mapped by spatial cells in the medial entorhinal cortex. Then I will switch to time, which is less well understood. I will show how episodic temporal information is encoded across scales from seconds to hours within the overall population state of the lateral entorhinal cortex. In the hippocampus, this task-dependent representation of time may be integrated with spatial inputs from medial entorhinal cortex, allowing it to store a unified representation of experience.