Roughly three-quarters of Chichester's Roman walls survive — a 1.5-mile circuit broadly following the late third-century AD original, much rebuilt in medieval times and now largely topped by Georgian and Victorian additions. A footpath runs along the top for most of the route, giving views down into back gardens, the cathedral close, and the bishop's palace gardens. The west and south sections are the most rewarding.
The walls are the spine of any walking tour of the historic city. Allow around an hour for the full circuit.