Maidstone prison is situated on the northern edge of the County Town of Kent. It was completed in 1819 and was constructed from local Kentish ragstone quarried from the site, to a design by architect Daniel Asher Alexander, and was the most advanced model of its time. The prison underwent a re-role in 2013 and is now a designated foreign national prison and Home Office Immigration Enforcement
There are four residential units at the prison: Kent wing, Medway wing, Thanet wing and Weald wing. There is also a segregation unit.
- Kent unit – built in 1850, holds up to 178 prisoners, mainly in single cells.
- Medway unit – built in 1966, holds 101 prisoners in single cells.
- Thanet unit – built in 1909 but extended in the 1970s to hold 174 prisoners in single cells.
- Weald unit – built in 2009, holds 149 prisoners.