The Shallow Sea

The Great Archipelago of Koru is a ring of islands surrounding a vast, shallow sea. 

Most people live their entire lives on a single island, but can always see others nearby, easily within a day's journey to each other by boat. 

The sea is filled with life. To us, it would resemble prehistoric, with creatures that thrived in the Cambrian world as if they never went extinct. Easily the most numerous creature is the trilobite. 

There are other creatures outside of the waters as well, but they are mostly insect and flying reptiles. The latter are reminiscent of the most elaborate creatures of our Cretaceous period. 

Dotting this strange landscape are the occasional ruin from another age. These are sometimes submerged beneath the waves. Some are rusted and broken, others frozen in time.