Small excavation resulting from the installation of a large sewer through St Mary's Steps as part of the works for the Southern Section of the Inner Relief Road. Areas available for excavation were limited by an overhead scaffold walkway. Initially one trench was opened measuring 1.0 x 3.4 metres but this was later expanded to the north, east and south. The investigation revealed a Roman drainage arch which was then used as a postern in the post-medieval period.<1>