Belmarsh Prison opened almost 25 years ago and was the first adult prison to be built in London since Wormwood Scrubs in 1874. The bulk of the prison is on a large site surrounded by a perimeter wall about 1 mile long.
The prison has 4 houseblocks, each 3 storey and each with 3 spurs. Each spur contains 42 single and double cells.
- HB1, prisoners serving long-term sentences and includes a newly established enhanced progression unit.
- HB2, prisoners serving short-term sentences and those on remand.
- HB3,new arrivals and includes a dedicated first night centre.
- HB4,prisoners undergoing detoxification and vulnerable prisoners.
- HSU, (high security unit) holds prisoners assessed as requiring a high level of security/care, including its own segregation facility and visits area.