The Olorun River, also referred to as the River Olorun (pronounced OH-loh-runn) flows through the heartland of Tortall. It feeds into the Emerald Ocean, presumably starting from [[Lake Tirragen]. It passes through Corus and Port Caynn. Between Corus and Port Caynn there is a broad open basin called the Little Lake. Near its beginning, the Olorun joins with the River Tirragen to become the main river.