Bruce Murray Space Image Library
Voyager 1's mosaic of Io's southern hemisphere
The mosaic reveals a number of volcanic features: paterae, flow fields, tholi, and plumes, in various shapes and sizes. Paterae in the south polar region tend to be larger than those nearer to the equator, suggestive of differences in lithospheric properties and magma source regions in Io's mantle.
Here are some of the named places visible: