Havana Harbor is the port of Havana, the capital of Cuba, and it is the main port in Cuba, excluding the US Guantanamo Bay Naval Base (GITMO); technically a territory of the United States, and not a Cuban possession. Most vessels coming to the island make port in Havana; it is where many of the more powerful heads are located.
In January 1898 the USS Maine, the largest vessel to come out of an American shipyard, was dispatched to Cuba to protect US interests. At the time over 8,000 US citizens resided in the country, and their safety couldn't be assured in the state of affairs at that time. On the fifteenth of February, the Maine was sunk by a mine in the harbor. It became a major rally call for the Spanish-American War, and it caused the US to finally intercede on Cuba's behalf. In 1910 the wreck was removed from the harbor, it was posing a hazard to navigation, and was sunk in deep water in the Gulf of Mexico with proper military ceremonies.