The Twin Lakes lie in the center of Metrya. Though technically one lake that narrows in the middle, they are generally considered separate bodies of water. The lakes do not have official names and are usually referred to by their cardinal directions (the Western Lake and the Eastern Lake).
The lakes are fed by innumerable rivers - most are small, though the Tyria River, originating in the Greenwall, and the Evros River, beginning in the Sentinel Peaks, carry great amounts of water during seasonal melts. The Peiros River is the sole outlet from the Twin Lakes, connecting the interior bodies of water to the Sea of Ersas to the east via a winding route.
The once pristine waters of the lakes have become gradually more polluted as industry in Metrya begins to be established. Especially around the capital and nearby Ithai, where growth in the nation has been particularly concentrated, waste and trash has begun to pile up along the shores and once beautiful beaches. This has caused great consternation among the druids of the region, many of whom have taken it upon themselves to preserve the waters.