PIC SHOWS:-Aerial views of the Belmarsh prison facilities, located in the Thamesmead area of the Royal Borough of Greenwich, in south-east London, England. The large walled compound is HM Prison Belmarsh is a Category A men's prison. The smaller walled compound is HM Prison Belmarsh West, a category B mens prison. The 2 separate blocks make up HMP/YOI ISIS, which is a young adult and category C training prison for young men and adults up to the age of 25. The prison is within the perimeter of HMP Belmarsh and comprises two house blocks each with four spurs of three landing.