I'll be visiting the ports of Split and Valletta and would like to know if these ports can be done on our own without scheduling a tour. Can we walk from the ship to the city?

You can spend many hours wandering around the city of Split without ever getting in a motorized vehicle. Diocletians Palace is right across the highway from where you will tender into. Enjoy the open-air market. Buy a necktie (they were created in Croatia) and enjoy some Split cherries. It's also peaceful to stroll around the harbor or you can spend time in numerous museums. The restaurant that sits right next to the tender area has some of the best lasagna that I have ever had the pleasure of eating. Enjoy yourself and don't spend too many kuna.

drlivingston--Thank you for info on Split. Do you have any advice on Ravenna?

Whoops, I meant Valletta.