The Epic of Aerth (Mytus/Dangerous Journeys) Paperback 1992
"Six Worlds in One! This is the sourcebook for the fantasy milieu you've always dreamed of! The world of Aerth is hauntingiy familiar, yet strangely mysterious. Visit Aeropa's Avillonian Isles, which include mighty Lyonnesse. See the "Dark Continent" of Afrik, travelling up the Nylle River, past Egypt's four great pyramids, to the unexplored lands of the interior. Or cruise the long reaches of the Mare Ostrum which reaches from eastern AEropa to the steppes of Central Azir. And then there are the Seven Lakes of distant Vargaard...."