We hired a private guide in advance, but it wasn't necessary. The wonder and beauty of Split is wandering on your own. Poke around through the back streets, you can't possibly get lost; just head for the water. Have lunch in a local spot, off the main drag.
We rented a car which enabled us to get away from Corfu Town into the countryside. Don't miss the Achilleon Palace! We took a quick walking swing through Corfu Town and were happy we'd not spent the day there because while architecturally charming,it is largely shops.
We arrived in the port of Chania (Souda), took the city shuttle bus from the port, and spent the day just wandering. It was very pleasant, enjoyed a relaxed lunch on the water. Like all the Greek islands, the people are very friendly.
We opted for the cruise line tour because it seemed like the simplest way to visit the Acropolis, our primary interest, and get an overview of the city. The experienced guide knew the ropes for moving us around the Acropolis before it was mobbed. It was a perfectly fine experience, nothing superior, but our goals were accomplished.
We anchored out, tendered in and spent the day exploring all the cobblestone byways, taking in the windmills and panorama of the port and sea. I was once again pleased by the attitude of Greek island shopkeepers. They are friendly, but not pushy to get a sale. The quality of their merchandise is excellent.
I give Santorini a high rating because of Oia, not the port of Fira. There are only three ways to get into Fira,hiking up on the donkey trail,the cable car or riding donkeys. When we got off the tender, the line for the cable car was tremendous (the cable car takes 36 people at a time...imagine that with three cruise ships in port..how many thousand?) and since our primary goal was to see Oia and have lunch there, we took a 35 E/pp boat ride direct to Oia...a visual jewel...and a private bus back to Fira (included in the boat fare). The cable car line in Fira was three times the size of the morning line so we decided to walk down the donkey trail. Big mistake. It's essentially a 600 step ski slope covered with slippery donkey manure and no handrail. Despite being sure footed,I skidded around a turn and bounced down several steps on my backside.It took nearly an hour and was dreadful. Don't miss Oia, but take the cable car down from Fira, no matter how long the line!
We rented a car with two other cruisers to visit Olympia and had arranged for a private guide recommended by Rick Steves. Sadly,due to a series of delays on our part and the difficulty communicating when you don't have a cell phone, we didn't hook up with her,as had been planned for weeks. It was entirely our fault and we were very disappointed. So, with Rick Steves guide to Olympia in hand, we made our way through the site. However, it would have been much more meaningful with a private guide. Olympia, the town is charming and we enjoyed lunch al fresco before returning to Katakolon which is largely touristy shops along the port's main drag.
We spent the night before the cruise in Venice and returned for a four day stay - which wasn't nearly long enough. Having tasted Venice, we didn't want to leave. I recommended a pre-cruise hotel in my review. Cruise Critic members who are interested in excellent/reasonable post-cruise accommodations can read my review of Residence Corte Grimani on the Trip Advisor web site. There's an old saying, "see Venice and die"...meaning once you've seen Venice, you've seen it all. Even though the original phrase was not about Venice, but Milan, it is true...Venice is like no other place in the world.