National human rights institutions should use their authority to make unannounced visits in order to ensure that inspections reveal the true state of affairs: for instance, the physical conditions of prisons—such as cleanliness and the quality and sufficiency of food—could be altered if inspections are conducted with advance warning. Similarly, individual detainees could be moved to another facility if there is advance warning of an inspection. This is why it is important for institutions to have the right to enter and inspect places of detention without prior authorization.