Lake Banyoles Nature · Banyoles, Pla de l'Estany, Girona The estany de Banyoles, in the Pla de l'Estany district (Gerona), is the largest natural lake in Catalonia, of tectonic and karstic origin, formed some 250,000 years ago when the movements that formed the Pyrenees opened up the Empordà fault. It covers 1.18 km², is 2.1 kilometres long and has an average depth of 15 metres, with a maximum of 40, at an altitude of 172 metres. It is fed mainly by groundwater filtering down from the Alta Garrotxa, with only 10% of its inflow coming from surface streams. It is home to the freshwater mussel Unio ravoisieri, found nowhere else on the Iberian Peninsula, and is designated a Ramsar wetland of international importance. In 1992 it hosted the rowing events of the Barcelona Olympic Games. Photo: Joanrcp~commonswiki (Wikimedia Commons) (CC BY 2.5) What to see and do in Banyoles