Defending a strip of land from the Atlantic to the west of the Great Lakes involved difficult choices. What areas should be given defence priority? Where should the great forts be located? From the very first, Quebec City, Kingston and Montreal were identified as strategic points for safeguarding the country, and it was imperative that these cities be made virtually impregnable. Citadels were therefore built in Quebec City and Kingston. Montreal was to be defended by forts to the south and an army in the field. Communications could be improved by digging various canals along the Richelieu River and around Montreal Island, and particularly by building locks on the Ottawa River and canals along the Rideau River. A second navigable channel between Montreal and Kingston was considered desirable in the event that the Americans took control of the St. Lawrence River between these two cities. Secondary works, consisting of strengthening almost every existing fort and erecting a citadel in the Niagara Peninsula, were also planned, to ensure that "the inhabitants would not think that we had abandoned them."