Why was Old Havana designated a UNESCO World Heritage site in 1982?

Old Havana and its historic fortifications were designated a UNESCO World Heritage site in 1982 because the district serves as one of the great treasuries of historic colonial architecture in the Western Hemisphere.1

The area is recognized for its rich collection of buildings representing diverse architectural styles from the 16th through the 19th centuries, including Spanish colonial structures, towering Baroque churches, and Neoclassic buildings. Furthermore, the site includes the extensive network of Spanish fortifications that once made Havana the most heavily fortified city in Spanish America, such as the Castillo de la Fuerza and Morro Castle. These elements collectively preserve the historical significance of the city, which was once known as the "Key to the New World and Rampart of the West Indies".23