Soloa is a land formed by a higher than typical concentration of volcanic activity. A subduction zone at the South creates a volcanic arc, which makes up the volatile Southern mountains. Aside from that it also lies over multiple volcanic hotspots which themselves form many individual volcanic craters. Throughout the planet's history the outflows of these hotspots joined together over time and formed the island.

Despite there always being some form of effusive eruption occurring somewhere on Soloa, life thrives here. Descendants of the viviparous lizard have evolved divergent lifestyles, with one the Soloan Beach Lizard (Vivipara litornicola) being primarily coastal with more aquatic tendencies, and the other species the Soloan Inland Lizard (Vivipara mediterraneus) being mainly inland with a tendency to stay clear of the ocean.

Unlike Polarcardiva which has no other tetrapods besides lizards, Soloa has sparrow descendants that have migrated over from Catland, if accidentally. The species found here is the Surf-running Sparrow (Domesticus salocursor). They are the descendants of sparrows that have survived many accidental island-to-island transitions across sea and have thus accumulated adaptations for coastal living, including sharper longer wings, longer and naked legs, and higher production rate of a hydrophobic dander produced by their skin. They find food either washed up on the beach or by running through shallow water where it meets the sand. They are also generalists that will eat insects, fruit and grains.