Listed Building: THE ROUND TOWER (1386901)

The Round Tower fortification, now museum. c1415. Ground floor reconstructed c1538-40. 2 upper storeys added probably late C17 by Sir Bernard de Gomme and remodified early C19, possibly for adaptation as a Martello Tower. Top raised and reconstructed and adapted as a gun platform c1850. Restored late C20. Ashlar stone. Roof asphalt paved. 3 storeys separated by stone string bands, lower storey projects. Cylindrical. Entrance facing Board Street has a 2-leaf panel door each leaf with a 6-pane glazed upper panel, set under a cambered stone arch. Facing the harbour on north and west sides are 3 gun ports each set under a flat segmental arch. 3 other gun ports were blocked up probably late C17 by Sir Bernard de Gomme. INTERIOR: rebuilt early C19 was reconstructed and has a large central stone column with brick vaulting, casements formed behind the surviving gun ports. (Balfour A: Portsmouth: London: 1970-: 15; Corney A: Fortifications in Old Portsmouth: Portsmouth City Museums: 1965-: 30, 31 AND 32; Lloyd DW: Buildings of Portsmouth and its Environs: Portsmouth: 1974-: 35,54-56,78,79,102; The Buildings of England: Pevsner N & Lloyd D: Hampshire and the Isle of Wight: Harmondsworth: 1967-: 422).