A wide strip of grass running along the seafront, kept clear of buildings since the 18th century to give the navy clear lines of fire on any French invader. Today it functions as the city's main outdoor space — kite-flying ground, festival venue, picnic spot, and an enjoyable place to walk between the major sights at either end (Southsea Castle, the D-Day Story, the Pyramids leisure pool, the Rose Garden).
The Naval Memorial — a tall obelisk listing thousands of Royal Navy sailors with no grave but the sea — stands at the western end of the common, near Clarence Pier. Big summer events including Victorious Festival are held here.