Jade Gates
From A Wiki of Ice and Fire
Straits of Qarth, is a narrow passage, located close to the great city of Qarth on the south coast of Essos and connecting the Summer Sea and the Jade Sea as such it's a major trade hub between the east and west. [1] from which Qarth derives it considerable wealth and power by taxing passing ships. The Straits are patrolled by the powerful Qartheen fleet.