The building, including the extensions, is a Grade I listed building.
The two schools were moved in the 1950s and the library in 1986. The museum expanded in to the city Guildhall in 1980 and with new space available from 1986 it underwent an extensive redevelopment over 1989-90 and again in 2000-01.
The museum houses the Human History Collection, most notable for antiquities associated with Hadrian's Wall and the two Roman forts established in Carlisle. It also has large and eclectic collections of zoological, botanical and geological material, as well as fine and decorative arts collections. paintings in the collection include works by Burne-Jones, Stanley Spencer, Winifred Nicholson, Sheila Fell and Phil Morsman.