I was there in 1958, just before everything was shut down. Havana was a jumpin' town to say the least. From what I've heard from Canadian friends that have been there in the past couple years Havana is essentially a ghost town in comparison to back then.
When I was in Guantanamo Bay the following year, no one was allowed to leave the Naval Base and go to Havana. Diving at Officer's Beach, which was on the base, was awesome. Underwater visibility back then was well in excess of 100 feet, spearfishing for monster grouper and yellowtail snapper was beyond your wildest dreams, and the local beer was called "Hatuey." It sold for .15 cents a bottle back then, and it was really strong. Today it sells for $8 for a six-pack and is brewed somewhere in the U.S..