Although I initialy planned to stay only in Havana and Trinidad, people kept recommending a visit to Vinales so I decided to take the 8h taxi journey there.
Vinales is a tiny place surrounded by a fantastic valey with a great landscape. It has again a completely different feel from Havana and Trinidad. There is almost nothing happening but if you like hiking or take a hose ride around the valey it's more than worth the stay there.
If you are in Vinales you should also go and visit Jesus in his Prehistoric Park. He is a great talker and knows a lot to make a very worthwile 30 minutes tour of his park.