We've experienced different charging policies for shuttles from the ship to the main point of interest depending on the cruise line. I know that there are charges to get to main cities like Rome (miles away from the port) but when a port is advertised, like 'Bilbao', for example, are you charged for a shuttle on Princess, or are shuttles complimentary? (Bilbao is an example where the main city is down the road from the more industrialised cruise port but still fairly local.)