Overview
Elsternest was established at Le Coudré, near Mirus. It was an 8cm Mortar battery, like that of Naumannshöhe. It was probably just earthworks
Purpose
Detection of landing attempts on Rocquaine Bay by surveillance of sea and airspace, as well as the defense of Rocquaine Bay against any landing attempts by cooperating with other defensive positions along the bay. The fort is to be defended against all attacks to the last man.