Aesheba: Greek Africa (1987)

From the back of the book:

Problem: Characters in your fantasy role-playing campaign have no new lands to explore.

Solution: Take the largest ocean in your fantasy game campaign, and add one continent. Start with Africa, circa 300 B.C., and shrink it a bit. Remove the Nile, so the Egyptians remain a primitive culture, and redesign the terrain features while leaving the ecology and climate about the same. Now add Greek colonists along the north coast, and let the whole thing brew for three centuries.

User Notes:
Book comes with a quality full color map.