The Cathedral of Havana is an iconic work of what is known as Cuban Baroque and the most remarkable of our colonial churches. The glorious baroque facade and asymmetrical bell-towers of the late 18th-century cathedral are the square’s top attraction. Its interior is surprisingly plain, but it once held the remains­ of Christopher Columbus. Religious services are held here. It has been declared a National Monument.

The vast Fortaleza de San Carlos de la Cabaña, known as ‘La Cabaña’, running beside the harbor, was constructed after the English capture of Havana in 1763. The largest of the military structures built by Spain in the Americas, this fortress was completed in 1774 and its presence formed an effective complete deterrent against the country's enemies. The polygon, occupying an area of around 10 hectares, consists of bastions, ravelins, moats, covered walkways, barracks, squares and stores.  It is impressively well preserved, and the gardens and ramparts are romantically lit in the evening. This fortress hosts the spectacular nightly ceremony of El Cañonazo de las Nueve (cannon fire at 9), the firing of a cannon that marked the closing of the city gates, one of Havana's longest-held and most attractive traditions.

The Cannon Blast ceremony (El Cañonazo de las Nueve) is one of the oldest and attractive traditions of Havana. In colonial days, the shots signalled the closing of the gates of the walled city and the rising of the chain across the entrance to the harbour. The tradition of firing a cannon every night at 9:00 pm was kept even after the wall was torn down and is still used for checking your watch.

The Real Force Castle is located in Old Havana, in an attractive area of important architectural, urban, cultural and social values. This is the oldest fortress of the former fortification system of Havana and the Americas, which construction dates back to 1577. It was declared a World Heritage Site by UNESCO. A replica of the La Giraldilla, the symbol of the city, can be seen on the highest tower of the castle (the original is in the Museum of the City). Since 2008, the Museo de Navegación (Maritime Museum) is located in the former moat of the Real Force Castle. This museum houses interesting exhibits detailing the history of the fortress and Old Havana, as well as its connections with the former Spanish Empire. It’s worth mentioning that huge scale model of the Santísima Trinidad galleon can be found here.