Gulf of Yrsa

The Gulf of Yrsa is a large, roughly semicircular embayment on Thelbiron’s coast with the Scarlet Sea. Its shores are notched with three further bays or gulfs, each relatively deep and narrow, formed by the estuaries of the three major rivers that drain into the Gulf. From west to east, these are are Siygur's Bay (into which flows the River Vaska), the Bay of Sirens (into which flows the River Tarba), and the Bay of Bothvar (into which flows the Kanis River). 
The Gulf of Yrsa, or more specifically the Bay of Sirens and the Tarba estuary, is generally considered to divide Tordynnar (to the east) from Haothana (to the west).