From Tar Valon Library
The Aryth Ocean is the large ocean separating the main continent from the Seanchan lands in the east. It is approximately ten thousand miles across (Map, TWoRJTWoT, Ch. 15). In the main continent, Arad Doman and Tarabon lie on the ocean, as does Saldaea, though the Banikhan mountains lie on the coast. The towns of Bandar Eban, Falme and Tanchico are all ports on the Aryth, and the Andahar and Dhagon flow into it In Seanchan, Rampore and Shon Kifar both lie on the Aryth Ocean. The Sea Folk have always refused to cross the ocean, claiming that the Islands of the Dead lay on the other side (TGH, Ch. 9). Most people did not believe it possible that the Seanchan could come from the other side of the Aryth Ocean (TGH, Ch. 9; TDR, Prologue; ACoS, Ch. 7). Tremalking and some of the other Sea Folk Isles lie in the Aryth Ocean.