The Southern Ocean is riddled with mesoscale eddies. Although just a few km in size, these loops and vortices are key parts of the climate system, and are important in controlling how ocean circulation responds to changes in forcing. Observations reveal that changes in the intensity of these eddies vary significantly around the Southern Ocean. This contrasts with the nature of the atmospheric forcing, which is more zonally symmetric. Recent progress using high-resolution modeling has pinpointed where intrinsic variability dominates over wind-driven variability, and hence the areas where future responses to climatic changes in forcing are likely to be clearest.