- 24 4. Conditions of detention in police establishments a. introduction 52. All police cells should be of a reasonable size for the number of people they are used to accommodate and have adequate lighting (i.e. sufficient to read by, sleeping periods excluded) and ventilation; preferably they should receive natural light. They should also be equipped with a means of rest (eg. a fixed seat or bench) and persons obliged to spend the night in custody should be provided with a mattress and clean blankets. Persons held by the police should be allowed to comply with the needs of nature when necessary, in clean and decent conditions, and should have adequate washing facilities. They should be given food at normal mealtimes, including a full meal (i.e. something more substantial than a sandwich) at least once a day. Persons held in police custody for extended periods should, as far as possible, be allowed a daily period of exercise in the open air. b. situation in the establishments visited 53. The conditions of detention in the police establishments visited varied from adequate to extremely poor. The conditions in the two cells at Larissa Police Headquarters and in two cells in the basement of Thessaloniki Police Headquarters were such that the CPT's delegation recommended that they be taken out of service immediately, pending the necessary improvements. The Greek authorities informed the CPT by letter of 21 May 1993 that the above-mentioned cells had been taken out of service. i. police stations/headquarters - Athens 54. The principal detention facilities at the Athens Police Headquarters were situated on the 7th floor of the Headquarters building. They consisted of 20 cells divided into two sections. The cells measured just over 12 m², and were equipped with fixed benches for rest/sleeping purposes; the lighting was adequate, as would be the ventilation in the absence of overcrowding. In principle, the cellular accommodation could be considered as acceptable for persons obliged to remain in police custody for a relatively short period, on condition that the premises are kept clean and those obliged to spend the night in custody are provided with mattresses and blankets. 55. However, the delegation found that in addition to criminal suspects (who might stay for a maximum of some four to six days - cf. paragraph 14), the Headquarters were being used to accommodate for lengthy periods persons held under the Aliens legislation. Many of these persons met by the delegation had been held in the Headquarters' detention facilities for periods in excess of a month, and a few had been there for over three months. Such a situation is not acceptable. The physical surroundings and the regime are quite unsuitable for such lengthy stays. There is not even the possibility of access to the open air: out of cell "exercise" is taken in a corridor adjacent to the cells.