Usk Prison was built in 1841/2 in red sandstone and extended in 1868. It opened in 1844 as a House of Correction, and after the addition of other buildings in 1870 the establishment became the Monmouthshire County Gaol, superseding the Monmouth County Gaol in Monmouth. It retained that role until 1922 when it closed, reopening in 1939 as a borstal. It continued as a borstal until 1964 when it became a Detention Centre. In 1983 Usk became a Youth Custody Centre and from 1988 to 1990 a Young Offenders Institution. In May 1990, Usk became an Adult Category C prison for Vulnerable Prisoners (mainly sex offenders) and it continues in that role today.