Originally called Batterie Nina, Batterie Mirus comprised four 30.5 cm guns - it became the largest artillery battery in the Channel Islands. 

The battery was constructed from November 1941 and through the first half of 1942, and was the largest battery in the Channel Islands, the guns having a maximum range of 51 km. Although the guns were removed in the early 1950s, the reinforced concrete structures and associated positions remain intact.