Huinay also divides the private Pumalín Park founded by American Douglas Tompkins into two parts.
Tompkins wants to purchase it to unify his park, however, this has met with strong opposition from the people in the hamlet of Huinay.
The Leptepu fjord is part of a 68 km (42 mi) longitudinal structural fault that runs from north to south, profoundly remodelled through the passing of the continental glaciers during the glaciations of the Quaternary period.
The ice field that slid through the fiord, trapped between the high mountains, carved the valleys deeply - they have subsequently been partially refilled with sediment, resulting in a remaining depth of up to 500 m below current sea level.
This, together with the abundant rainfall, sustains the thick, evergreen, mixed, mild jungle that extends to the high-water mark along the walls of the fjord.