If you have the time to explore more of Cuba, I highly recommend the city of Trinidad. It was founded in 1514 and sits on the southern part of the island. It is one of the best preserved cities in the Caribbean from the time when the sugar trade was the main industry in the region. It was named an UNESCO World Heritage site in 1988.
The cobblestone streets and pastel-colored houses transport you back to colonial times. Many of the houses contain iron grilles, wooden doors and arched windows. You will also see birdcages on many structures. It is a wonderful city to walk and explore. There are numerous galleries and cafes. You can find paper mache items as well as Naif paintings which are of Afro-Caribbean inspiration depicting landscapes and street views of the colonial towns.
I recommend staying at the Iberorstar Grand Hotel Trinidad in town. The restaurant was excellent and the hotel was easy walking distance from the center or Plaza Mayor.