We arranged a guide with either Tours by Locals or Withlocals (can't remember which) for 3 days before the cruise. She met us at the Rome airport and we spent three days in and around Viterbo. Highly recommend it! Viterbo - don't miss Palazzo Farnese and Villa Lante. Civita di Bagnoregio is incredible. She took us to the embarkation point at the end. Don't stay in the port city!