Yaros

Yaros is a small island in Slaver's Bay, located just off the coast southwest from Yunkai, though it is apparently the largest island in Slaver's Bay itself (which is bounded to the west by the large Isle of Cedars). Yaros lies directly between Yunkai and Astapor,

Season 4
Yaros is marked on a map of Slaver's Bay that Ser Jorah Mormont is looking over.

In the books
In the A Song of Ice and Fire novels, Yaros is much the same.