Mancera Island is a minor island at the mouth of Valdivia River

Valdivia River

The Valdivia River or Río Valdivia, as it is known locally, is a major river in southern Chile. It is the continuation of the Calle-Calle River, from the point where it meets the Cau-Cau River in the city of Valdivia. The Valdivia river ends in Corral Bay, on the Pacific coast. Other tributaries...

, in southern Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

. It was named after the Spanish viceroy of Peru Pedro de Toledo, 1st Marquis of Mancera, who fortified the island. The fort was a vital point in the Valdivian Fort System

Valdivian Fort System

The Fort System of Valdivia are a series of Spanish colonial fortifications at Corral Bay, Valdivia and Cruces River established to protect the city of Valdivia, in southern Chile. During the period of Spanish rule , it was one of the biggest systems of fortification in the Americas. It was also a...

, preventing enemy ships from reaching Valdivia

Valdivia, Chile

Valdivia is a city and commune in southern Chile administered by the Municipality of Valdivia. The city is named after its founder Pedro de Valdivia and is located at the confluence of the Calle-Calle, Valdivia and Cau-Cau Rivers, approximately east of the coastal towns of Corral and Niebla...

 from Corral Bay

Corral Bay

Corral Bay is a bay in the mouth of the Valdivia River, southern Chile. Its main towns are Corral and Niebla. The mouth of the bay is between Juan Latorre point and Morro Gonzalo, with a width of 5.5 km. All the year the bay is transited by merchant, transport and fish boats...

. The highest point of Mancera Island is 89 meters. The island is inhabited by 53 people according to INE's 2002 census.