from Wikipedia Havana:
Havana (Spanish: La Habana (help·info), IPA: [la aˈβana], officially Ciudad de La Habana, is the capital city, major port, and leading commercial centre of Cuba. The city is one of the 14 Cuban provinces. The city/province has 2.1 million inhabitants, and the urban area over 2.6 million, making Havana the largest city in both Cuba and the Caribbean region. The city extends mostly westward and southward from the bay, which is entered through a narrow inlet and which divides into three main harbours: Marimelena, Guasabacoa, and Atarés. The sluggish Almendares River traverses the city from south to north, entering the Straits of Florida a few miles west of the bay.
King Philip II of Spain granted Havana the title of City in 1592 and a royal decree in 1634 recognized its importance by officially designated as the "Key to the New World and Rampart of the West Indies". Havana's coat of arms carries this inscription. The Spaniards began building fortifications, and in 1553 they transferred the governor's residence to Havana from Santiago de Cuba on the eastern end of the island, thus making Havana the de facto capital. The importance of harbour fortifications was early recognized as English, French, and Dutch sea marauders attacked the city in the 16th century. The sinking of the U.S. battleship Maine in Havana's harbor in 1898 was the immediate cause of the Spanish-American War.
Nowadays Havana is the center of the Cuban government, and various ministries and headquarters of businesses are based there.