This area was declared a Nature Sanctuary in 1981, and in the same year it was included in the "Convention on Wetlands of International Importance".
It was formed after the earthquake which destroyed the area in 1960; agricultural land subsided, and was left submerged to a depth of 1 to 2 meters. Subsequently it was colonized by vegetation, which made a home for aquatic fauna, especially birds.

There are at present 119 species living in the wetland and adjoining areas. Amongst others there are black-necked swans, coots, coscoroba swans, marsh crows, coypu and river otters.

Casa Andwandter
Carlos Andwandter is an example of the enterprising and tenacious character of the first German settlers in the south of Chile. After arriving in Valdivia in 1850 he acquired a piece of land in Isla Teja, where he set up a brewery which brought great prosperity to his family and to the area. In 1860 he built his house next to the brewery. It is a simple, sober structure, two stories high, built of roble timber on stone foundations. The west front consists of a porch with doors, a style traditional in the area since the Spanish colonial period. It has a two-pitched roof covered with galvanized iron.