Event/Activity EPM57 - An Archaeological Watching Brief at Portsmouth Grammar School, High Street, Portsmouth, Hants

An archaeological watching brief carried out at Portsmouth Grammar School, as a result of a proposal to build an extension to an existing hall on the site (the hall was a modern school building). As the site was situated within the medieval old town of Portsmouth, it was thought there was the potential for archaeology. A total of 17 footing trenches were dug around the existing modern building, the majority in the larger area to the north. The trenches were roughly rectangular in form, some being over 2 metres deep in order to reach undisturbed geology. The archaeology on the site consisted entireley of the remains of the 19th century Borough Gaol prison block and Clarence Barracks. Deep thick walls associated with the prison were found along the western end of the site and along the eastern boundary north of the building to be extended. Shallower walls and concrete layers excavated along the northern edge of the building to be extended were associated with Clarence Barracks. Large quantities of brick and rubble found in the footing trenches were thoughht to be associated with the prison and the demolition of Clarence Barracks.