The Battle of Mount Tumbledown was an engagement during the Falklands War. The engagement was an attack by the British Army and the Royal Marines on the heights over-looking Stanley, the Falkland Islands capital. Mount Tumbledown, Mount William and Sapper Hill lie west of the capital. Due to their proximity to the capital, they were of strategic importance during the 1982 War. They were held by the Argentine 5th Naval Infantry Battalion (BIM 5), a reinforced, cold weather trained and equipped, Marine battalion.