The Complete Guide to Phantasy Star III

Rhys' quest begins in the world of Landen.

 Overworld Landen Town Satera Castle Passage to Aquatica
 Overworld (with bridge) Landen Castle Yaata Town Passage to Aquatica (with treasure chests)
Island Cave Landen Dungeon Ilan Town Passage to Aridia
Island Cave (with treasure chests) Landen Dungeon (with treasure chests) Sunken Palace Passage to Aridia (with treasure chests)
      Passage to Elysium
      Passage to Elysium (with treasure chests)

Lyle's home world is devastated by an unusually harsh winter. The ruins of Orakio's fortress may lead to the solution.

Overworld Cille Town Shusoran Town Passage to Landen
Overworld (Frozen) Cille Castle Shusoran Castle Passage to Landen (with treasure chests)
Rysel Town Cille Dungeon Shusoran Dungeon  Passage to Aridia
Rysel Town (Frozen) Cille Dungeon (with treasure chests) Shusoran Dungeon (with treasure chests) Passage to Aridia (with treasure chests)
Agoe Town Sage Isle
 Agoe Castle  Sage Isle (with treasure chests)

The desert climate of Aridia makes it suitable for cyborg habitation only. Legends speak of "Laya's Treasure" being buried somewhere in this world.

Overworld Weather & Satellite Control - Floor 1 Passage to Landen Passage to Aquatica
Hazatak Town Weather & Satellite Control - Floor 1 (with treasure chests) Passage to Landen (with treasure chests) Passage to Aquatica (with treasure chests)
Whirlpool (Laya's Palace) Weather & Satellite Control - Floor 2 Passage to Draconia Passage to Frigidia
Western Cave Weather & Satellite Control - Floor 2 (with treasure chests) Passage to Draconia (with treasure chests) Passage to Frigidia (with treasure chests)
Western Cave (with treasure chests)

The villages of Draconia find themselves under siege from Siren's army that pours out of Techna Castle.

Overworld Lensol Town Techna Town Passage to Aridia
Endora Town Lensol Castle Techna Castle Passage to Aridia (with treasure chests)
Lensol Dungeon Techna Dungeon (Passage to Azura)
Lensol Dungeon (with treasure chests) Techna Dungeon (Passage to Azura) (with treasure chests)

Elysium was once the world of pilots, but they vanished over centuries. Now a small band of rebels are plotting their resistance against a recently awakened Lune here.

Overworld Divisia Castle Aerone Town Passage to Landen
North Divisia Town Divisia Dungeon Aerone Dungeon (Passage to Dahlia) Passage to Landen (with treasure chests)
South Divisia Town Divisia Dungeon (with treasure chests) Aerone Dungeon (Passage to Dahlia) (with treasure chests) Rebel Cave
Rebel Cave (with treasure chests)

This frozen world contains a village of historians and Laya's hometown.

Overworld Mystoke Town Mystoke Castle Skyhaven Castle
Passage to Aridia  New Mota Town Mystoke Dungeon Skyhaven Dungeon
Passage to Aridia (with treasure chests) Mystoke Dungeon (with treasure chests) Skyhaven Dungeon (with treasure chests)

The world of Terminus was so corrupted by evil that its entrances were permanently sealed. Only one city remains in this world.

Overworld City of LaShute LaShute Dungeon LaShute Dungeon (with treasure chests)

Dahlia Moon
Orakio banished Lune and his sister Alair to Dahlia 1,000 years ago. They placed themselves, and their army, in a cryogenic sleep until the opportunity to strike arose again.

Dahlia Surface Dungeon Dungeon (with treasure chests)  

Azura Moon
Laya banished Siren and his army to Azura. 1,000 years of waiting have driven Siren mad and seeking revenge on Laya's descendants.

Azura Surface Dungeon  Dungeon (with treasure chests)  

I've given permission to several other sites to use these maps, even sent them the source files used to create them.,, and are a couple that come to mind. I'm sure other sites have used them without permission. No big deal, the maps are Sega's copyright (not mine) anyway. If you've seen a Phantasy Star III map online chances are I made it back in 2000.