The World of Ys mirror much of the real world where the visited continents so far are Eresia and Afroca. These two continents are mostly inhabited by Eresians and Afrocans with a minute number of wing ones called the Eldeen.
The Ys series has taken place mostly in the continent of Eresia which have been conquered by the Romun Empire whose seat of power lies in Romn. The Romun forces have extended south across the Medo Sea to the continent of Afroca which has claimed the city of Xandria. This encouragement to the Kingdom of Altago later saw the two regional powers going to war for naval supremecy. The result was a truce that merely deterred the Empire's expansion temporarily.
Across the ocean to the west is The Great Vortex which is explored in Ys VI: The Ark of Napishtim. The Romun had sent forces near the vortex lead by Admiral Agares and Ernst to scout the land within the vortex.
Each game happens in a part: