Los Lagos Region is one of Chile's 16 regions, which are first order administrative divisions, and comprises four provinces: Chiloé, Llanquihue, Osorno and Palena. The region contains the country's second largest island, Chiloé, and the second largest lake, Llanquihue. Its capital is Puerto Montt; other important cities include Osorno, Castro, Ancud, and Puerto Varas. The mainland portion of Los Lagos Region south of Reloncaví Sound is considered part of Patagonia.