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With a surface of 368 hectares it is also the biggest glacial lake

Glacial lake

A glacial lake is a lake with origins in a melted glacier. Near the end of the last glacial period, roughly 10,000 years ago, glaciers began to retreat. A retreating glacier often left behind large deposits of ice in hollows between drumlins or hills. As the ice age ended, these melted to create...

 in the Iberian Peninsula

Iberian Peninsula

The Iberian Peninsula , sometimes called Iberia, is located in the extreme southwest of Europe and includes the modern-day sovereign states of Spain, Portugal and Andorra, as well as the British Overseas Territory of Gibraltar...

.

The Sanabria lake is now within the limits of the Sanabria Lake Natural Park

Sanabria Lake Natural Park

The Sanabria Lake Natural Park is a natural park located around Lake Sanabria in the Sanabria comarca, northwest part of the Zamora province, in the mountainous area of Sierra Segundera and Sierra de la Cabrera...

. The area was declared a Natural Park in 1978.

The Sanabria comarca is one of the few areas in Western Europe having a sizeable population of wild wolves living in the Sierra de la Culebra

Sierra de la Culebra

The Sierra de la Culebra, , is a mountain range in north west Spain and northeastern Portugal. It lies 7 km south of Puebla de Sanabria in the comarcas of Aliste, Sanabria and La Carballeda , as well as Vinhais and Bragança municipalities in the District of Bragança...

mountain range.