Presentation The Spanish Parliament, through Organic Act 1/2009, of 3 November, agreed to entrust the Ombudsman’s Office with the functions of National Preventative Mechanism against Torture, pursuant to the Optional Protocol to the Convention against Torture and other Cruel, Inhuman or Degrading Treatment or Punishment (NPM) of the United Nations. The assignment of these powers implies, firstly, trust in the institution to perform these functions and, also, a great responsibility to be discharged with the utmost professionalism, reporting annually to the Spanish Parliament and to the Subcommittee on Prevention of Torture of the United Nations (SPT). To perform these functions, all kinds of centres for deprivation of liberty are visited, including those of the National Police Corps, the police of the autonomous governments, local police and the Civil Guards. Penitentiary centres, centres for the protection of minors, hospitals with custody units, centres of border controls and centres for the internment of foreign nationals, with participation in repatriation flights. The regular visits made to the centres have the purpose of detecting eventual deficiencies, suggesting improvements or evaluating correct actions and conveying the results and making the appropriate recommendations to the responsible authorities. The technical experts of the institution are accompanied by specialists of various professional centres to fully appreciate the aspects that should be assessed, such as infrastructures, healthcare, psychological counselling, legal assistance, visits regime, communications, surveillance methods and, accordingly, absolute respect to human rights. The duration of the visits is several days in order to observe all the facilities and hold interviews with the inmates and also with the personnel of the centres. In addition, an Advisory Council exists formed by persons proposed by the professional associations, whose members also participate in the visits, preparing reports and observations to be taken into account. Three centres for the internment of foreign nationals were visited in London, Paris and Rotterdam, to compare their operating procedures and make recommendations of the good practices observed. After five years discharging the entrusted functions, a set of criteria and rules exists to be used as guidelines to carry out the assessments contained in this report, which ends with the recommendations made. The Annexes, in electronic format, render full account of all the visits made. 5