Just back from a fantastic cruise on Britannia to the western med. for 12 nights. We booked this last year and, as we knew all the ports well, had no intention of getting off much. We actually only got off twice - in Lisbon and Cartegena - and were gone only an hour or so at both. However, all of the ports are great and well worth either a guided tour with P&O or a walk on your own.
We had fantastic weather - between 29 and 35 degrees centigrade most of the time.
Britannia is a wonderful ship - very modern interior and very classy. We were on her in her maiden season last year and she is still as wonderful.
Only got off and walked to the edge of the town as we've been here before. Very nice, reasonably quiet place. Good Roman remains if you're interested in that sort of thing. A lovely seafront promenade to walk along as well.