English: Schematic illustration of the structure of zones and microzones in the cerebellum,using three levels of magnification. On the left is a simplified illustration of what the cerebellar cortex would look like if all the folds were straightened out: the vertical dimension is the rostro-caudal axis of the cerebellum, the horizontal dimension is the medio-lateral axis. A "zone" is a longitudinally oriented strip of the cortex, and a "microzone" is a thin, longitudinally oriented portion of a zone. As the illustration on the right shows, Purkinje cell dendritic trees are flattened in a way that aligns with the microzone length, and parallel fibers cross the microzones at right angles.