Pontypool Park House was sold to the Sisters of the Order of the Holy Ghost in 1923, who utilised the building as a girls' boarding school. It eventually became St. Alban's R.C. High School. The adjacent stable block was used for a variety of purposes during the 20th century but ultimately became home to the Valley Inheritance Museum (Amgueddfa Torfaen Museum) in 1981, which was set up by Torfaen Museum Trust (est. 1978) to accommodate, safeguard and present the collections relating to the heritage of the Afon Lwyd valley.