Rocca dei Rettori is Benevento's old seat of power, a compact fortress-palace where the city's layers are unusually easy to read. A Lombard tower anchors the complex, while the later governors' palace speaks to the period when Benevento was controlled by papal rectors rather than local princes.
It is worth stopping here even if you are mainly in town for Santa Sofia and the Arch of Trajan. The rocca stands high enough to give a sense of Benevento's position between river valleys, and its museum spaces and garden fragments fill in the local story without requiring a long visit. The exterior alone rewards a short detour through the historic centre.