The selection of a healthy site for a barrack building or new military station is a matter of great importance. In the earlier days of barrack construction, barracks were, for political reasons, usually built in large towns, where troops would be at hand for putting down disturbances, and cramped and inconvenient buildings of many storeys, were erected on a small piece of ground often surrounded by the worst slums of the city; such, for example, were the Ship Street barracks in Dublin, and the cavalry barracks at Hulme, Manchester. Worse still were cases where an existing building, such as the Linen Hall in Dublin, was purchased, and converted into barracks with little regard for the convenience of the occupants, and a total disregard for the need of a free circulation of pure air in and about the buildings, which is the first condition of health. In the present day, except in a few cases where strong local influence is allowed to prevail to retain troops in towns, where their presence, and perhaps the money they spend, are appreciated for patriotic or other motives, every opportunity is taken to move troops from the vicinity of crowded towns, and quarter them in barracks or hutments built in the open country.
Due regard can then be given to sanitary location, and military training can more effectively be carried out. With improvements in communication by rail, road and telegraph, support to the civil power in case of disturbance can always be afforded in good time, without permanently stationing troops in the actual locality where their assistance may be needed. It has been recognized ever since the Crimean War, that the leading principle of barrack policy must, in the future, be to facilitate in peace time the training of the army for war, and that this can only be done by quartering troops in large bodies, including all branches of the service, in positions where they have space for training, gun and rifle practice, and manoeuvring. The camps at Aldershot, Colchester, Shorncliffe and Curragh were accordingly started between 1856 and 1860, and the same policy has since been continued by the acquisition of Strensall Common, near York, Kilworth domain, near Fermoy, the lease of a portion of Dartmoor and a large area at Glen Imaal in Co. Wicklow, and the purchase of the Stobs estate in Scotland and of a large part of Salisbury Plain.